This Fitterfirst Door Hook is a sturdy nylon loop with a folded end to secure it in any door. Close a door on the folded end so it is secure, and put your tubing or banding through the open loop.
When you attach any resistance band or tube to the top of a doorway it gives you a wider range of possible exercises for arms, shoulders, and elbows. By securing it lower down and combining with ankle/wrist cuffs you can work lower-angle exercises with arms and legs. These are a great way to add versatility and flexibility to any resistance training routine.