Kneeboard Rack For Boat, Polished Aluminum Kneeboard Wakeboard Combo Rack, Wake board Wakeboarding Rack For Towers Tubing Sizes 1 3/4", 1 7/8", 2", 2 1/4", 2 3/8", 2 1/2" Clamp Sizes: 1 3/4", 1 7/8", 2", 2 1/4", 2 3/8", 2 1/2" Full Size Kneeboard Rack - Fits both vertical and horizontal tower bars at virtually any angle Secures 2 Boards 1 x Kneeboard and 1 x wakeboard American Owned Company Double Polished 6061 Aluminum