Our ergonomic, latex-free, anti-burst 52cm fitness ball keeps your spine aligned and core engaged while you work. This balance ball can be used on its own, or within the frame of several of our Balance Ball Chair options. When used alone it is great for exercise ball workouts, core exercises, stretching, and as a Pilates balance ball. Whether used for fitness or as an active seat, improve balance, abdominal strength, and overall fitness. Made to fit several of Gaiam’s Balance Ball Chairs Improves balance and fitness Strengthens core muscles Ergonomic back support Reduces nerve compression Professional-grade, anti-burst exercise ball Great for core and Pilates workouts Use for stretching exercises Measurements: 52cm. Materials: Vinyl. Latex-free. Compatibility: Classic Balance Ball Chair, Backless Balance Ball Chair, Ultimate Balance Ball Chair, and Ultimate Balance Ball Chair with Swivel. Instructions: After initial inflation let the ball stretch for 24 hours and re-inflate.