The Step Original Aerobic Platform &ndash; Circuit Size Made in the United States from durable, recyclable high-density polyethylene Includes circuit-size (28.5 L x 14.5 W x 4 H) black aerobic platform and 2 original grey risers Platform features grooved, nonslip top and supports up to 275 lbs Four nonskid feet on each riser and platform prevents sliding or scratching floors Vary workout difficulty by adjusting platform height from 4 to 6 using risers