Ueasy Bounce trainer training device Jump trainer Leg strength and agility training strap Play a very active role in the basketball and volleyball training jumping sports training needs Color: Red-80pounds, Black-60pounds, Blue-40 pounds, Yellow-70pounds, Purple-50 pounds, Orange-100 pounds (have it's different pounds) Specifications: elastic rope length 35 cm total length 40CM Ueasy Bounce trainer training device Leg strength and agility training strap 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.