How high can you go? That's what you'll find out when you use the Tandem TSVERTICAL Vertical Challenger Jump Trainer. Better yet the more you try the higher you'll get. Before you know it you'll be spiking volleyballs to exact locations on the court with ease. With this Vertical Challenger Jump Trainer you can get a jump on the competition with the most affordable and accurate device on the market for measuring vertical jump! Telescopes from 4 to 12 feet. Movable arms placed at 1" increments allow for accurate jump measurement. Highest arm reached remains angled until jump reading is measured. The heavy duty base is fitted with easy glide casters providing both stability and portability. Vertical Challenger comes with handy reset pole.