Wellsem Speed Agility and Strength Leg Resistance Jump trainer ( Taekwondo Fitness Exercise Tool Equipment ) Strength :about 50lbs Packing content: 4 band+2 leg strap +1 Carry bag Strengthen leg, hip, and core muscles to improve athletic performance; running speed, vertical jump, endurance Ideal for use during speed and agility training for all sports Used worldwide by athletes, coaches, trainers, physical therapists, and healthy minded people of all ages (7+)