I believe most trailers are 2″ now days. I dont know of any bigger, so if your trailer fits on a 2″ ball it should be fine. The other common sized trailer ball is 1 7/8″ and if the trailer was made for that it wouldnt fit on a 2″ ball.Last edited by toledobasser on April 17th, 2011, 10:37 pm, edited 1 time in total.Jim EbarbMany, LA (Toledo Bend Lake)2004 Cougar/ 225 OptimaxHumminbird Helix 12 Chirp SI on BalzOut Mount at bowLowrance HDS 7 at bowHumminbird Helix 12 Mega SI on Ram Mount at ConsoleLowrance HDS 8 in dash at console