The TUT Trainer™️ Tower Cable Lock is ingenious. Clip the Cable Lock onto the TUT Trainer™️ Tower cable and snap on the carabiner. Now you can attach single "D" handles or the 19" aluminum bar and perform a myriad of exercises. And, its adjustable. Simply pinch the silver lever to slide up and down the cable and position the Cable Lock where you want it; based upon your height and/or the exercise you want perform. When pulling downward on the Cable Lock, the Cable Lock securely grasps and locks onto the cable. Refer to installation video.