HIGHLY ADJUTABLE: Sit-up machine can adjusts to three different gears for any foot size by flexible spring buckle, helping to hold your feet in place during exercise. SUPERIOR MATERIAL: Seleted super-elastic wear-resistant eco-friendly foam materail, comfortable and safe, ptotect the instep from pain, as well as not hurt your foot. WIDE USE: Can be used for roll belly movement, push-ups, side kick, sit-ups ,stretching back,elbow plank,press-up to exercise the abdomen and tighten the whole body muscles, yoga exercise hands and legs, a variety of functions application. Suitable for fitness men & women. Convenient for doing sit-ups every day, especially for busy people who don't have so much time doing exercise. EASY INSTALLATION: Small occupation, easy to install and disassemble, quickly assembly simply take a few minutes, convenient to use.