SPART AEROBIC MODULAR STEP
This set includes a grey platform with premium comfort cushion top and four original black risers to create the foundation for any workout program. 
The Original Health Club Size platform features a wide 40" L x 14" W x 4" H stepping surface with a nonslip grip for added safety and a comfort cushion (non-latex) top that is easy on the hands, feet, and back. Burn more calories the higher you step with 4"-8" platform height options using the 16" L x 16" W x 2" H risers. Each riser and platform is made with four nonskid feet to prevent sliding or moving during exercise. These sturdy risers can be used on any type of indoor flooring from carpet to concrete to hardwood without leaving behind scratches. 
The Step is a great home-fitness tool for beginners to experts and is customizable for a variety of aerobic and strength exercises. This set is crafted from durable, recyclable high-density polyethylene that supports up to 300 pounds (or up to 500 lbs with risers). This product is backed by a 90-day manufacturer's warranty period.
Made from durable, recyclable high-density polyethylene
Includes full-size (40" L x 14"X4") grey aerobic platform and 4 original black risers
Platform features premium nonslip, comfort cushion top and supports up to 300 lbs
Four nonskid feet on each riser and platform prevents sliding or scratching floors
Vary workout difficulty by adjusting platform height from 4"-8"  using risers