Size:25cm Function:Twisting abdominal muscles, stimulate abdominal muscles. Massage the foot bottom to promote blood circulation. Ball-bearing Ride:Precision ball-bearing ride for smooth, fluid motion, High-impact, rotating platform provides a vigorous form of aerobic exercise. Benefit to Health:Effectively burns calories and combines the benefits of aerobic exercise with reflexology. Premium Material:Environmental plastic waist twist board, also a good balance board for fitness. This Waist Twisting Disc will let you so sports and exercise at home or outdoor places. With Massage Point: With massage point on the surface, it is a good fitness trainer to be put in your home, use it to exercise your waist, massage point on the surface will promote blood circulation, make your body relax during exercise. Weight Loss Equipment Keep using it, shrink your abdomen, let your weight slowly decrease, and it is also a health disc, it is a good weight loss equipment for women.