The Aerobic Stepper Set offers a safe, non-slip surface for workout and rehabilitation routines that involve step aerobics. It is used to easily workout all the major muscles in the lower body, as well as tone the calves and quads. It is the ideal choice for beginners and experts. Additional risers allow the step height to be adjusted, increasing the stepping challenge. Each set of risers will increase the stepper height by 2 inches. This set comes with two sets of risers. The Aerobic Stepper itself measures 43" L x 16" W x 4" H and has a weight capacity of 300 lbs. The Aerobic Stepper placed on risers has a weight capacity of 500 lbs.