High-quality mini exercise balance ball. The ProBody Pilates Mini Exercise ball is intended for core strength, balance, back rehabilitation and for toning and sculpting with Pilates, Yoga or other fitness exercises. Anti-burst balls do not include a valve, but rather have a plug to withstand high pressure. This requires a straw for inflation, which can provide some amusement while inflating. Soft PVC material that is free of the six common harmful phthalates: DEHP, DBP, BBP, DINP, DIDP, and DNOP. Recommended by trainers and physicial therapist. Exercise balls are perfect to increase balance, core strength and flexibility.