Review on Enhanced BlueFire 7 Way Heavy Duty Trailer Connector Plug Cord with Weatherproof 7 Gang Junction Box (6 Feet) - Ideal for Trailers and RVs by Noah Smith

Cable, molded plug, socket, fittings - all beautiful and durable. The attached pinout diagram was accurate (I tested the functions on my truck and they were all fine). I stole the idea from another reviewer of putting extra nuts on top of the assembled one. Post to attach my connections - but in my case the thread was metric 5mm x 0.8 (rather than the suggested 10-32). Be sure to test it before you buy any devices. I also added an o-ring into the groove in the lid where it connects to the box. I'm not sure if that helps, but I don't think it harms the waterproofing.