Chiaogoo tighten keys are used 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 our 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. Available in Small (Fits Small [S] or Large [L]) or MINI.