Madison 20 inch hardside expandable carry-on spinner; the abs hardshell material is designed to absorb impact under stress and 'flex' back into its original shape. (the chevron print is constructed of a tough polycarbonate/abs shell); multi-directional ez-glide 4-wheel spinners for smooth, effortless 360 degree movement over any type of surface; spinner wheels allow complete upright mobility for free-weight rolling, relieving pressure from your arms