This is an Original Thermo King part for type Unit:
AMD-M1                        
AMD-M2                        
AMD-M2 met TK3'9'5 Engine     
AT10-HTP©                     
AT10-M1                       
AT10-M10                      
AT10-M11                      
AT10-M12                      
AT10-M13                      
AT10-M14                      
AT10-M15                      
AT10-M16                      
AT10-M1A                      
AT10-M2                       
AT10-M3                       
AT10-M3A                      
AT10-M3B                      
AT10-M4                       
AT10-M5                       
AT10-M6A                      
AT10-M7                       
AT11                          
AT12                          
BKD MAX met TK3'7'4 Engine    
CBci, CBci2 & CB              
CBci2 & STBci2 EEC            
CD MAX & CD MAX EEC           
CD-II MAX & CD-II MAX EEC     
CG-II
CG-II M12 voor Sea Container  
CG-II M12B & M12C             
CG-II M17, M17A & M17B        
CG-II M20                     
CG-II M22, M22D, M22E         
CG-II M22C                    
CG-II M22F voor Crowley       
CG-II M30C voor Crowley       
CG-II M30D                    
CG-II M323A                   
CG-II M324                    
CG-II M40                     
CG-II M7 voor CGM             
CG-II M7A voor CGM            
CG-II M8A & M8B               
Fresh King met TK2'4'9        
HK-III HO met TK2'4'9         
HK-III zonder 380V met TK2'4'9
JD-II met TK2'4'9 Engine      
KD-II
KD-II MAX met TK3'6'6 Engine
KD-II SR met TK3'7'4
MD-II & MD-II MAX             
MD-II MAX met TK3'7'4 Engine  
MD-II TCI
MD-II TCI met TK3'7'4         
MD-II TCI-Z                   
MD-II TLE met TK3'7'4 Engine  
MD-MT                         
NWE MAX                       
PGM MAX & PGM-II MAX          
R1 M1                         
R2 M1                         
R2 M1E                        
R2 M2                         
R2 M3                         
R2 M4                         
R2 M4E                        
R6-M5                         
RD-II 50 TCI-Z                
RD-II MAX met TK3'8'8
RD-II MAX met TK3'9'5
RD-II met TK3'8'8
RD-II met TK3'9'5
RD-II TCI met TK3'9'5 Engine  
RD-II TCI-Z EEC met TK3'9'5   
RD-II TLE                     
RMU-II                        
SD-I 1012 M1                  
Sentry 1500 met C2'0'1        
Sentry 3000 met C2'0'1        
Sentry di                     
Sentry II MAX met se2'2 Engine
Sentry II MAX TC met D2'0'1   
Sentry MAX met di2'2 Engine   
SGCM                          
SGCM 2000 Tier 2 Engine       
SGCM 3000 Maersk              
SGCO 2000                     
SGCO 2000 Tier 2 Engine       
STBci & STBci2                
Super TD-II met TK3'9'5 Engine
T11-M1-M21 & THU11 M1         
T2-M12                        
T3 M34
T3 M35
T3 M37
T3 M39
T3 Series M19, M20, M22-M25   
T3 Series M40 Thru M48 
T3-M26 & THU3 M1              
T3-M28                        
T3-M29                        
T3-M29E                       
T3-M30                        
T3-M31                        
T3-M32                        
T3-M33                        
TCI EEC met TK3'7'4           
TCI-Z EEC met TK3'7'4         
TD-II
TD-II MAX             
TD-II MAX met TK3'9'5
TD-II met TK3'9'5
Transit Bus Air Conditioning  
TS-200 met TK3'7'4
TS-300 met TK3'7'4
TS-500 EMEIA met TK3'7'6
TS-500 met TK3'7'6
TS-500 met TK3'9'5
TS-600 EEC met TK3'95         
TS-600 EMEIA met TK3'7'6
TS-H-TP©                      
URD 25DG                      
URD-III 25DG                  
URD-III 25DG met 3'9'5 Engine 
URD-III 50 MAX TCIA           
URD-III 50 TCIA               
V-250                         
V-280                         
ThermoKing Part Description:
LOCKNUT
LOCKNUT (1/2-13)
LOCKWASHER
NUT
NUT - evaporator
NUT - pulley
NUT - strap
NUT - unit
NUT (1/2-13)
NUT (1/2-13, hexstop)
NUT (1/2-13, stop)
NUT (hexstop)
NUT (stop)
Thermo-King no. 55-4952 / 1098A42H10
Old numbers: 
55-5040/1099A97H17
57-3900/1099A97H17
Description on packing: 
55-4952
Nut, Hexstop SS
Made in US
Examples and applications or 
Names and unit codes: 
TK55-4952 / TK-554952 / TK.55.4952 / TK554952
TK55-5040 / TK-555040 / TK.55.5040 / TK555040
TK57-3900 / TK-573900 / TK.57.3900 / TK573900
Ford Transit/FordTransit/Airco                                                                                                                              
T2M12 / T2 M12                                                                                                                                              
CDIIMAX / CD II MAX / CD-II-MAX / CD2MAX / CD 2 MAX / CD-2-MAX / CDIIMAXEEC / CD II MAX EEC / CD-II-MAX-EEC / CD2MAXEEC / CD 2 MAX EEC / CD-2-MAX-EEC       
AMDM2/AMD M2                                                                                                                                                
HTP@TS200
AT10M1 / AT10 M1 / AT 10 M1 / AT-10-M1                                                                                                                      
NWEMAX / NWE-MAX                                                                                                                                            
T3M30 / T3 M30                                                                                                                                              
T3M32 / T3 M32                                                                                                                                              
TS 500
CDMAX / CDMAXEEC                                                                                                                                            
HattinkPGMMAX / PGMIIMAX / PGM II MAX / PGM-II-MAX / PGM2MAX / PGM 2 MAX / PGM-2-MAX                                                                               
TS_300
TS 600
MD2TCi
MDIITCIZ / MD II TCI Z / MD-II-TCI-Z / MD2TCIZ / MD 2 TCI Z / MD-2-TCI-Z                                                                                    
FreshKing                                                                                                                                                   
CGIIM17 / CG II M17 / CG-II-M17 / CG2M17 / CG 2 M17 / CG-2-M17 / CGIIM17A / CG II M17A 
TDII / TD II / TD2 / TD 2 /TD-2                                                
RIIMIII/RII MIII/R2M3                                                                                                                                       
RIIMIE/RII MIE/R2M1E                                                                                                                                        
CuijkHattinkSentryIIMAXTC/Sentry2MAXTC                                                                                                                                  
AT10M14 / AT10 M14 / AT 10 M14 / AT-10-M14                                                                                                                  
T3-M19 / T3-M20 / T3-M20 /T3-M22 / T3-M25 / T3M19 / T3M20 / T3M20 /T3M22 / T3M25
CGIIM20 / CG II M20 / CG-II-M20 / CG2M20 / CG 2 M20 / CG-2-M20                                                                                              
AT10M11 / AT10 M11 / AT 10 M11 / AT-10-M11                                                                                                                  
CGIIM30C/CG2M30C/CG-2M30C                                                                                                                                   
URDIII25DG / URD III 25 DG / URD-III-25DG / URD325DG / URD 3 25 DG / URD-3-25DG                                                                             
HTP@CGIIM7A/CG2M7A/CG-2M7A                                                                                                                                      
HTP@SGCM2000Tier2Engine                                                                                                                                         
KDII / KD II / KD2 / KD 2 / KD-2
KDIIMAX / KD II MAX / KD-II-MAX / KD2MAX / KD 2 MAX / KD-2-MAX
@HTPCGIIM7/CG2M7/CG-2M7                                                                                                                                         
BKDMAX                                                                                                                                                      
CBci 2 / CBci-2                                                                                                                                             
MDIITCI
SGCM                                                                                                                                                        
CGIIM12/CG2M12/CG-2M12                                                                                                                                      
T3M26 / T3 M26 / THU3-M1 / THU3M1                                                                                                                           
CuijkHattinkSentry3000 / Sentry-3000                                                                                                                                    
SentryIIMAX / Sentry-II-MAX / Sentry2MAX / Sentry 2 MAX / Sentry-2-MAX                                                                                      
AT10M13 / AT10 M13 / AT 10 M13 / AT-10-M13                                                                                                                  
AMDM2 / AMD M2                                                                                                                                              
AT10M5 / AT10 M5 / AT 10 M5 / AT-10-M5                                                                                                                      
CGIIM22C / CG II M22C / CG-II-M22C / CG2M22C / CG 2 M22C / CG-2-M22C                                                                                        
MDII / MD II / MDIIMAX / MD II MAX / MD-II-MAX                                                                                                              
Sentrydi                                                                                                                                                    
CGIIM40 / CG II M40 / CG-II-M40 / CG2M40 / CG 2 M40 / CG-2-M40                                                                                              
TS_500
TS500EMEIA
RIIMIIII/RII MIIII/R2M4                                                                                                                                     
MD2TCI/MD-2TCI/MDIITCI                                                                                                                                      
HattinkThermo-Parts.nl                                                                                                                                                            
CGIIM22 / CG II M22 / CG-II-M22 / CG2M22 / CG 2 M22 / CG-2-M22 / CGIIM22D / CG II M22D
AT10M6A / AT10 M6A / AT 10 M6A / AT-10-M6A                                                                                                                  
T11M1 / T11 M1 / T11-M21 / T11M21 / T11 M21                                                                                                                 
V250 / V 250                                                                                                                                                
JDII / JD II / JD2 / JD 2 / JD-2                                                                                                                            
CGIIM12B / CG II M12B / CG-II-M12B / CG2M12B / CG 2 M12B / CG-2-M12B / CGIIM12C / CG II M12C / CG-II-M12C / CG2M12C / CG 2 M12C / CG-2-M12C                 
TS-300
AT10M3 / AT10 M3 / AT 10 M3 / AT-10-M3                                                                                                                      
SentryMAX                                                                                                                                                   
SGSM3000Maersk                                                                                                                                              
SGCO2000Tier2Engine                                                                                                                                         
Hattink Heesch.comT3M33 / T3 M33                                                                                                                                              
HattinkThermo-Parts.nlTS_600
AT10M16 / AT10 M16 / AT 10 M16 / AT-10-M16                                                                                                                  
MDIIMAX / MD II MAX / MD-II-MAX / MD2MAX / MD 2 MAX / MD-2-MAX                                                                                              
TS/600
CGIIM323A / CG II M323A / CG-II-M323A / CG2M323A / CG 2 M323A / CG-2-M323A                                                                                  
T3M29E / T3 M29E                                                                                                                                            
MDMT / MD MT                                                                                                                                                
TS_200
RD2TCIZEEC/RDII                                                                                                                                             
TS/500
AT-12 / AT 12 / AT12                                                                                                                                        
T3-M40 / T3-M48 / T3M40 / T3M48
TS600EEC / TS 600 EEC                                                                                                                                       
HH@AT-11 / AT 11                                                                                                                                               
@HHURDIII50TCIA / URD III 50 TCIA / URD-III-50-TCIA / URD350TCIA / URD 3 50 TCIA / URD-3-5-TCIA                                                                
URDIII50MAXTCIA / URD III 50 MAX TCIA / URD-III-50-MAX-TCIA / URD350MAXTCIA / URD 3 50 MAX TCIA / URD-3-50-MAX-TCIA                                         
TS300
RDIITLE / RD II TLE / RD-II-TLE / RD2TLE / RD 2 TLE / RD-2-TLE                                                                                              
Sentry1500 / Sentry-1500                                                                                                                                    
R6M5 / R6 M5                                                                                                                                                
AT10M2 / AT10 M2 / AT 10 M2 / AT-10-M2                                                                                                                      
SGCO2000                                                                                                                                                    
RMUII / RMU II / RMU2 / RMU 2 / RMU-2                                                                                                                       
HTP@TS/200
HKIII/HK III/HK-3/HK3/HK 3                                                                                                                                  
AMDM1/AMD M1                                                                                                                                                
RDIITCI / RD II TCI / RD-II-TCI / RD2TCI / RD 2 TCI / RD-2-TCI                                                                                              
AT10M10 / AT10 M10 / AT 10 M10 / AT-10-M10                                                                                                                  
KDIISR
RDII50TCIZ / RD II 50 TCI Z / RD-II-50-TCI-Z / RD250TCIZ / RD 2 50 TCI Z / RD-2-50-TCI-Z                                                                    
CGIIM30D / CG II M30D / CG-II-M30D / CG2M30D / CG 2 M30D / CG-2-M30D                                                                                        
URD25DG / URD 25 DG                                                                                                                                         
 CG-II-M17A / CG2M17A / CG 2 M17A / CG-2-M17A 
Hattink Heesch.comT3M28 / T3 M28                                                                                                                                              
HattinkHeeschSTB ci / STB-ci / STB ci 2 / STB-ci-2                                                                                                                       
RIIMII/RII MII/R2M2                                                                                                                                         
 CG-II-M22D / CG2M22D / CG 2 M22D / CG-2-M22D
T3-M34 / T3-M35 / T3-M37 / T3-M39 /T3M34 / T3M35 / T3M37 / T3M39 
CGIIM8A / CG II M8A / CG-II-M8A / CG2M8A / CG 2 M8A / CG-2-M8A / CGIIM8B / CG II M8B / CG-II-M8B / CG2M8B / CG 2 M8B / CG-2-M8B                             
V280 / V 280                                                                                                                                                
CG2M22F/CG-2M22F/CFIIM22F                                                                                                                                   
KD-IISR
KD II SR
MD-2TCI
AT10M7 / AT10 M7 / AT 10 M7 / AT-10-M7                                                                                                                      
SuperTDII / Super TD II / Super-TD-II / SuperTD2 / Super TD 2 / Super-TD-2                                                                                  
@HTPTCIEEC/TC1EEC                                                                                                                                               
CBci 2 / CBci-2 / STBci 2 EEC / STBci-2                                                                                                                     
SDI1012M1 / SD I 1012 M1 / SD11012M1 / SD 1 1012 M1 / SD-1-1012-M1                                                                                          
T3M29 / T3 M29                                                                                                                                              
TS600EMEIA
TS-500
AT10M3B / AT10 M3B / AT 10 M3B / AT-10-M3B                                                                                                                  
HattinkCuijkTDIIMAX / TD II MAX / TD-II-MAX / TD2MAX / TD 2 MAX / TD-2-MAX   
TCIZEEC/TC1ZEEC                                                                                                                                             
Hattink Heesch.nlMDII / MD II / MD2 / MD 2 / MD-2 TK374 Engine
RIIMIIIIE/RII MIIIIE/R2M4E                                                                                                                                  
RDIIMAX
CGIIM324 / CG II M324 / CG-II-M324 / CG2M324 / CG 2 M324 / CG-2-M324                                                                                        
AT10M15 / AT10 M15 / AT 10 M15 / AT-10-M15                                                                                                                  
TS-600
AT10M1A / AT10 M1A / AT 10 M1A / AT-10-M1A                                                                                                                  
RIMI/RI MI/R1M1                                                                                                                                             
T3M31 / T3 M31                                                                                                                                              
AT10M12 / AT10 M12 / AT 10 M12 / AT-10-M12                                                                                                                  
TS 200
RIIMI/RII MI/R2M1                                                                                                                                           
TS500
AT10M3A / AT10 M3A / AT 10 M3A / AT-10-M3A                                                                                                                  
AT10M4 / AT10 M4 / AT 10 M4 / AT-10-M4                                                                                                                      
Pressure Valve Regulator / throttlingvalve / throttling valve / Suction Regulator / RegulatorSuction / Regulator Suction / Inlet pressure Regulator / pressure Regulator Inlet / Valve Pressure Regulator / pressure Inlet Regulator  / VALVE throttling /