SKLZ Chrome Hopz Pro Vertical Jump Trainer The vertical jump is a key component to athletic ability. Using the SKLZ Chrome Hopz Pro, athletes will develop explosive leg drive and power for increasing their vertical. With up to 80 pounds of resistance, this performance trainer pushes athletes to the next level. The set includes a heavy-duty vest, 4 resistance cords, ankle straps with foot harnesses and a carry bag. The vest uses welded rings for variable attachment points. Resistance bands are then able to quickly attach and release to both the ankle straps and the vest. The bands vary in levels of resistance, up to 80 pounds. Recommended user height: 5'4'' to 6'2''.