Material: iron tube + foam + natural rubber + PP + thick rubber suction cup, strong suction force, firm and safe. Extremely comfortable and safe, Instep protects from pain and does not injure the foot. Suitable for the whole family! ADJUSTABLE: The Sit-Up can be adjusted to three different gears for each foot size by a flexible spring clip to keep your feet in place during exercise. EASY TO INSTALL: It is very easy to install the foot perch at home without tools. Just to find a dry and clean flat floor, push the spring clip inward to adjust the height of the crossbar and push the black button up or down, go to the suction cup/fix it. Before you start exercising, please make sure it is not easy to move. COMPACT AND LIGHT: The training device is compact, light and very practical for training at home or traveling. Space saving and very practical for storage and transport anywhere, perfect for home fitness. It can be used for abdominal rolling movements, solid exercises, side kicks, sit-ups, back extensions, abdominal presses and whole body muscle toning, yoga practice and so on. Satisfactory Service: Freely refund or exchange provided. Try Camfosy Our best efforts to serve our customers, if you have any question about the products, please feel free to contact us, we will solve the problem for you within 24 hours.