Made in the United States from durable, recyclable high-density polyethylene | Includes circuit-size (28. 5” L x 14. 5” W x 4” H) grey aerobic platform and black 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 | Set includes a grey nonslip platform and two original black risers to create the foundation of any workout program