Ueasy Bounce Trainer Training Device Leg Strength Vertical Jump Trainer Freedom Combination Equipment ATTENTION: ELASTIC ROPE ONLY, need to use together with Waistband and Ankle straps. If you don't have the Waistband + Ankle straps, you have to order one. Play a very active role in the basketball and volleyball training jumping sports training needs. Belt Color: Red-80pounds, Black-60pounds, Blue-40 pounds, Yellow-70pounds, Purple-50 pounds (have it's different pounds). From a biomechanical point of view to improve the leg strength to do anything you can do to achieve the squat action or participate in any sport, for enhancing the jump, speed and strength are very helpful with rubber foot ring / ring is adjustable wrist, snap Department can add more elastic rope to increase resistance. Free combination of different tensile strength, step by step to enhance the strength.