Inertia WaveDoor Anchors replace the Rail Straps of the SOLO & STRONG. These are specifically designed for your door jams. Just feed the straps through the back of the door jam on both sides 40 inches off the floor. Close and Lock the door. Omit the rail anchors that came with your kit, and replace them with door anchors. This is for those who want intense fat-burning, core smoking! workout in the privacy of their own home!