The 121583-0000 is a 4-position black (RAL 9005) Circular Plug with socket type tin-plated copper alloy contacts. The APD series circular connector has PBT housing, HNBR O-ring and PA coupling nut. The direct, in-line and bulkhead sensor connector is resistant to engine, transmission and brake fluid. It also boasts very low contact resistance, so can benefit from maximum signal integrity.