Molded composite foam rollers are perfect for positioning, balance, postural and muscle re-education, spinal stabilization, body awareness and coordination, and ranging and strengthening activities. Half round roller is a great tool for ankle stretching and knee rehabilitation. Diameter refers to the width of the half-round profile. The molded rollers are strong enough to be used by large adults and active children. This line of rollers is available in black. The molded composite foam rollers are more firm than the polyethylene roller and are rugged.