New Ultra RIGID Non Rattle design. Available for round tube - mount fits 1.5" to 2" or flat bar mount. Holds 2 boards (available for 2 skis). Boards are O-ring insert protected. Quickly and easily removes with "Knob Release" design. The Perfect Fit Our R&D boys worked long and hard on this one! We wanted a clamp that could hold the weight of 2 boards though white caps without slipping. We wanted a clamp that would fit all towers with "style." We did it. This clamping system will fit 1.5" diameter tube all the way to 2". It is 5 inches long with a fluted grip jaw, secured by 6 stainless bolts for a truly "SLIP FREE" fit. oves with "Knob Release" design.