Made of 100% high quality rubber, these balls are regulation size and weight and meets CLA specifications for official use in games. Every ball is stamped for verification. The Official Lacrosse balls are the ideal size and density for massage and to relieve muscle pain. They are great for trigger point release, tight and sore muscles, acupressure relief, plantar fasciitis pain, and knots. High quality rubber makes them a great toy for pets and dogs.