Each keyed DC Receptacle is compatible with the matching keyed DC Battery Connector. As an example the Key A TI2005-410 DC Battery Connector WILL NOT mate with the Key B TI2004-020 DC Battery Receptacle. They must be the same Key to fit properly; This is a safety measure. Picture shows a sample of what NOT to do. Key A is compatible with the Military standard MS3509.
DC Battery Connector | 
    DC Battery Receptacle | 
  
![]() Key A TI2005-410  | 
    ![]() Key A TI2005-379 / NSN: 5935-01-594-9348  | 
  
| Key A uses the Military standard MS3509 and comes standard with all Tesla™ 28 Vdc Ground Power Units and (MPU) Aircraft Battery Systems. | |
![]() Key B TI2004-021  | 
    ![]() Key B TI2004-020  | 
    
| Key B is the standard for all Tesla 12 Vdc on Ground Power Units. | |
![]() Key C TI2004-108  | 
    ![]() Key C TI2004-109  |