The massage lacrosse balls are made with molded rubber construction, making them perfect for training, tournament, and competitive game play. Comply with the NCAA standards, this lacrosse ball is certified to improve shooting accuracy, handling during gameplay and practice. Lacrosse balls are multifunctional across many other platforms to improve your health and quality of life: foot massage, physical therapy, back pain, sore muscle relief, myofascial trigger points and many more massage therapy. 2.5" Diameter