RV Designer P725 Black Pollak 6 Way Round to 7 Way Socket Adapter. Plug is die-cast metal with high impact interior. Brass terminal pins for best conductivity accept up to 12 gauge wires. Car-end only 7-way blade style socket of durable nylon with spring loaded door to keep out dust and moisture. Two 1/4" mounting holes on 6-way socket, 2-7/8" on center. Mounts through 1-3/8" hole.