1/4" microphone/guitar connector.
Stainless mounting plate, heavy nickel plated electrical contacts, and 18 gauge tinned wiring provide excellent corrosion resistance. Open design cannot trap moisture. Compatible with all lights using 1/4" phone jack connectors. 
Do NOT use hole plugs with MOONLITE female connectors. Most types of hole plugs do not keep water out but will prevent moisture evaporation.