Made of high quality plastic and spring, much stronger, durable and difficult to crack, best choice for building up your muscles. Both standing and sitting use are ok. Different using method for different exercise. Ideal for toning & strengthening stomach, waist and legs, arms, hips, thighs and works on the tummy at the same time. This resistance training tool workouts your arms, tummy, shoulders, legs and butt. It is not only way to lose your fat by exercising with our tummy trimmer but also a way to shape your body. Portable and light weight, easy to store and can be used anywhere anytime though in office.