This rugged cast aluminum rope tightener combines a strong carabiner with a cam locking mechanism, allowing you to secure, tension, and connect serious loads using a rope. Clip the carabiner to a fixed anchor point, then slide your rope through the cam mechanism for a knot-free and worry-free connection, easily releasing your rope with a simple pull. The small Cord Tightener fits cords 2mm to 5mm in diameter, and the large Rope Tightener fits ropes 3mm to 9mm in diameter.