GoFit Core Stability Disk for Balance, Core Strength and Ab Workouts, Yoga, Pilates Vinyl The Core Stability Disk is an excellent way to add a new level of difficulty to your workout. The soft disk can be utilized in pilates, yoga or regular workouts to work your core muscles, increase balance and stability. DETAILS: Difficulty may be increased by adding air or decreased by releasing air. Comes with a training manual to optimize your knowledge of the product and exercises. BENEFITS: The Core Disk will help you build a strong core, improving power and balance while decreasing the likelihood of injuries. Improved balance, abdominal strength, and muscle tone can provide a fuller, healthier life. FEATURES: One Core Stability Disk, Training Manual, and Inflation Needle (pump for inflation not included) GoFit's ongoing vision links the right product, and the best training, with people ready to make a dramatic, positive change. Are you ready for a fitness philosophy that gets results? Train. Recover. Repeat.