The hollow strap-on is perfect for beginners and can be worn by either partner. For men with ED (erectile dysfunction), the hollow strap-on allows you both to enjoy the passion of face-to-face sex without the untimely midway letdowns. Every strap of the silicone harness easily adjusts to fit most sizes, and the harness stays in place comfortably when the action heats up. To adjust, just slide the straps until the waistband is snug and the thigh straps feel tight, then connect the plastic Smart Clips in the back by hooking them together. The straps won't move and won't come loose during the heat of the moment.