1 Premium material: A very sturdy sit-up aid! The suction force of the strong suction cup is 4 times that of the ordinary suction cup, which can firmly grasp the ground. The center bar of the Hamstring Curl Band is made of steel for maximum stability and control. Thickened, curved, non-slip, cushioned high-density foam padding provides comfortable foot or ankle support. And high-grade nylon webbing.2 Multiple uses: 4 proven ways to use. Train anytime, anywhere and don't let your environment limit your workouts! Use for reverse crunches, leg raises, ab workouts, classic crunches, crunches and more! The hamstring curl machine is suitable for fitness enthusiasts of all ages.3 Exercise equipment: The sit-up aid is the perfect waist and abs exercise equipment. Allows you to better practice sit-ups by placing your feet on the floor and maximizing activation of your core abdominal and hip flexor form.4 Easy to set up: The sophisticated design makes the device easy for anyone to use. Do not use this device with glass doors!5 Portable: It's easy to put in a backpack or suitcase, it's very convenient whether you're on business trips, business trips or going to the gym.