The polished stainless steel round bar accessory clamp is used for safe, secure positioning of round bar accessories. It accommodates all round bar accessories 1/4" up to 3/4" diameter. This clamp features the ergo style tightening knob, chosen for both its ergo function and classy look.This premium quality clamp is of solid stainless steel construction. It easily attaches to the side rails of all North American surgical tables.