The Marcy Pro PM-20 leg developer is an accessory that adapts to the Marcy Pro PM 3800 Power Rack + Bench. The leg developer is designed to isolate and target the most powerful muscles in the human body-the quads and hamstrings. See explosive gains in both power and speed and by the end of the day, you"ll walk away knowing that you"ve just trained on the best equipment around. Backed by a manufacturer"s 2 year limited warranty.