When screwing in your tips, connectors or stoppers, insert this tightening key(s) into the lifeline hole found on each metal join at the ends of your TWIST & SPIN cables, connectors or stoppers. Simply use the key as a handle to help you grasp and tighten the screw connection. Use the key EVERY time you attach your tips to a cable. For an even better connection, try using the heart-shaped rubber gripper wrapped around the tip with the key. You will need the key to loosen the connection when removing the tips from the cable. Item Number: 2503-S/L (fits into Small [S] and large [L] interchangeable cable lifeline holes)