The is a round-style wiring harness that's 12-volt DC compatible. The adapter features a rugged, durable molded-plastic housing that resists corrosion so it's well suited for use in marine applications such as a boat trailer. This wiring adapter connects flat-blade brass terminals to flat pin-style tin-plated terminals.• 12V DC• Round-style wiring harness• 7-way to 5-way adapter Perfect for marine applications like boat trailers Connects flat-blade brass terminals to flat pin-style tin-plated terminals 12V DC | Boating Essentials 7-Way to 5-Way Trailer Wiring Adapter