They are mounted on a 2x4 and have bungy straps to attach to back of boat or trailer. Take them off when you get to ramp and throw in your truck. Never submerge your trailer lights. 4 prong attachment + grounding. Don't ask me how long the wires are or anything else - can splice if need longer wires or different connector. Worked great last time I used them. No guarantees, but they are free. Just PM me if you want them and I'll give you my address. I'm in Cbad. Pls don't waste my time - if you're not going to pick them up right away, let somebody else take them.