Engineered to eliminate sloppiness, the Companion series offers the smoothest ride on the road. The Companion attaches to your Turnoverball under-bed mounting system, which means you can pull a fifth-wheel or gooseneck hitch with the same system. Just like the Turnoverball, the Companion gives you easy install and removal without sacrificing sturdiness, reliability, or towing power. RVK3500 consists of two boxes: RVB3500 and RVC3006