Features: Adjustable size : The smart hula fitness hoop consists of 24 detachable parts, which can be split and reassembled to adjust the waist circumference. You can choose your own hula fitness hoop according to your waist circumference. 2 in 1 fitness and massage : This smart hula fitness ; hoop can quickly consume body fat and eliminate fatigue. You can not only exercise, but also massage your waist to achieve a relaxed state. Ideal for sports, fitness, weight loss and entertainment. 360-degree massage surround : Under the centrifugal movement of the 0.5 lb ; gravity ball, the shock-absorbing massage contact is fully in contact with the muscles, and the inertial slide rail can massage all the muscles of the waist 360, and the fat burning speed is 2-3 times faster than that of ordinary hula fitness hoop . 30 minutes a day can strengthen the waist. Non-dropping design : Using a flexible axis to ensure rolling at a constant speed and maintain smooth exercise. Rotate the weight ball, the smart hula fitness hoop will not fall. Let you get your ideal figure comfortably. Not recommended for elderly people! Adjustable strength :Adjust the length of the strap to adjust the exercise intensity, the shorter the rope, the greater the strength. Specifications: Knots Quantity: 24 Minimum inner diameter approx. 18cm.( 14 Knots) Maximum inner diameter approx. 38 cm.( 24 Knots) Minimum waist circumference approx. 56 cm.(