Premium-quality DC Plug and Receptacle Features unique locking blades with the industry’s largest surface-area for maximum surface contact and electrical conductivity. ConnectPro connections are weather resistant. The marine-grade design includes corrosion resistant, plated-brass electrical components, and a watertight sealing cap. The plugs ergonomic, soft-contoured grip allows easy hook-up and blade alignment. An O-ring seals out moisture while plugged into the receptacle. The receptacle has exclusive Perma-Lock terminals, meaning they virtually never need to be retightened.