Extra firm, smooth black cheap cylinder rollers are too hard, and only compress muscle tissue. Our patented massaging texture spreads and pinches muscle tissue to soothe knots, just like an expensive massage from a chiropractic or sports medicine office. Release knots and painful adhesions ifrom any muscle group. Perform balance exercises by standing on the 5 inch round diameter, or allow the spiky texture to massage the arches of your feet for plantar fasciitis. Great as an anti-cellulite tool for the back of your legs or buttocks, but also great to treat the muscles that lead to lower back pain.