Physical Therapy Massage Balls (6 PACK) 6 Lacrosse Balsl, Vulcanized rubber, Orange (also used for Back Massage Ball Therapy) Works great for massaging out trigger points/muscle knots, Lacrosse Balls work wonders for back pain, Lacrosse Balls work great for back massage Lacrosse Balls work great for dog toy balls NFHS approved NOCSAE stamped