The Smart weighted Hula Hoop is the right solution to your weight loss worries. Add this smart hula hoop to your exercise program and see the results. Even if you do it for a few minutes couple of times a day, it will be effective. This product helps you meet your exercise goals and gives you aerobic activity. Size Guidelines: · 18 knots are suitable for waist of 90cm/35.43inch · 21 knots are suitable for waist of 105cm/41.34inch · 24 knots are suitable for waist of 120cm / 47.24inch Small Sized Ball: 11*7cm (4.3*2.8in) Rope Length: 25cm (9.8in)