KLB Sport 28" Adjustable Aerobic Stepper Platform For Outdoor & Indoor( Black & Grey) plastic Imported Set of 2 risers that measure 16" by 16" Non-slip surface on platform that supports up to 550 pounds Adjusts from 4.89 to 6.93 to 8.97 for all heights and fitness levels Dimensions (cm): 27.56L X 11.03W X 4.89H Money Back Guarantee If You Will Be Not 100% Satisfied with Your Purchase