Flip Over Gooseneck Trailer Hitch for Semi-Tractors Installs behind 5th wheel hitch on standard 34" frames. Because the Flip-Over ball rotates in its socket, hitch ball and socket are kept clean and gooseneck hitch coupler life is greatly extended. They don`t "grind" against each other when you tow. The other advantage of a rotating ball is that it stays "free" in its socket so you can easily turn it over when you want a level floor in your truck. Requires 10" on top of the frame and 4" down each side. Mounts with three 3/4" bolts on each side. Fabricated from 1/2" high-grade steel. Complete with 2 5/16" ball and mounting hardware. The gooseneck hitch ball is locked in the one-piece machined steel socket with a spring loaded stainless steel pin. Simply rotate the handle to retract the pin, pull the ball out and store it inverted and out of the way in the socket giving full access to the fifth-wheel hitch.