The Yamaha HexrackII Accessory Clamp is used for securing tubes of different thickness (15 34 including hexagonal tubes) to an extended arm. These clamps can be used to secure tubes positioned far from each other. Each clamp has a gear joint enabling fine angle adjustment. With a synthetic sleeve HexRackII clamps get a rock solid grip on the rails. As the clamp tightens it compresses the sleeve to establish a solid grip. This gives the clamp a secure slip-free hold on the rail when tightened and allows easy adjustment when loosened making the whole setup process quick easy flexible and solid.