SKLZ Hopz Vertical Leap Trainer Develop explosive leg drive and power while maximizing your vertical leaping ability with the SKLZ Hopz Vertical Leap Trainer. Durable bands with resistance up to 40 lbs. Resistance bands quickly attach and release to the ankle straps and belt rings. Ankle straps with built in shoe harness keeps resistance bands in place. Adjustable belt fits most waist sizes. Recommended user height: 5'4'' to 6'2''