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 cables, connectors or stoppers. Use the key as a handle to help you grasp and tighten the screw connection. You will need the key to loosen the connection when removing the tips from the cable. Use it EVERY time you attach your tips to a cable to make sure they are securely fastened.