The door anchor allows you to do exercises at home which require you to wrap your cable around something. To use it, simply close the cylinder section of the cable onto the opposite side of the door to the rest of it. Then thread your cable through the loop. Depending on the exercise you can fix your anchor in different positions. If you need a high anchor, you can put your door anchor on top of the door. If you need a low anchor you can put your door anchor at the bottom of the door. Prior to using the door anchor make sure that the door is closed and will not open during exercising.