Perfect for positioning, balance, postural and muscle reeducation, spinal stabilization, body awareness and coordination, and ranging and strengthening activities. Round rollers offer progressive exercise sequences user can move from an easier smaller diameter to a more difficult larger diameter roller. Half round roller is a great tool for ankle stretching and knee rehabilitation. Use half roll as rocker board by standing on flat side. Diameter refers to the width of the half round profile. The ethafoam rolls and half rolls are strong enough to be used by large adults and active children. Foam rollers are available in 48', 36' and 12' lengths with either a round circular or half round semicircular profile. Foam rollers can be used alone or with other exercisers such as Cando exercise band, tubing, weights and balls. Standard white rollers in every size, including the newest extra sturdy, jumbo 8' diameter! TufCoat foam rollers for washability, firmness and durability Blue