SKLZ Hopz Vertical Jump Trainer with Free SKLZ Carry Bag Hopz Vertical Jump Trainer with quick attach resistance bands, ankle straps, and adjustable waist belt Helps athletes develop key muscles in the lower body for vertical leap ability Resistance bands quickly attach and release to ankle straps and belt rings Durable bands offer resistance of up to 40 pounds Recommended height range from 5 feet, 4 inches to 6 feet, 2 inches; fits most waist sizes