Adjustable size : The smart hula hoop consists of 24 detachable parts, which can be split and reassembled to adjust the waist circumference. You can choose your own hula hoop according to your waist circumference. 2 in 1 fitness and massage : This smart hula 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 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 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 Maximum circumference of the waist approx. 127 cm ;(24 ;Knots) Color: Pink Ball weight approx. 300g (sand inside,can open the ball to add or reduce weight) Package: 1 Set of 24 Knots Hula Hoops