GM 56 Series were the standard OEM connectors used on 1950-1980 US made vehicles. Replacement Female Housing for .250\" Locking Female (PICO #1599). Unit then mates with Male housing unit (PICO #1862). Units were created to securely lock together with male & female contacts making a positive connection. Bodies can be disconnected for terminal replacement if needed. Female Terminal (PICO #1599) sold separately.