The Fit Chair is perfect for performing any core exercise. Its patented steel bar secures the ball while you work out, and its special caster design locks for exercising and unlocks for seating. The chair also has an extra wide base with a deep inset that keeps the ball stationary during exercises.Features. Extra wide base with deep insert keeps ball stationary for performing exercises. Ideal for performing any core exercise position. Includes chair base, anti-burst ball, tube set, and hand pump. Patented steel bar secures ball while performing exercises. Special caster design, locks for performing exercises and unlocks for seatingSpecifications. Color: Black. Origin: Taiwan. Material: PE (Polyethylene), PVC. Latex: No. Phthalates: Yes. Dimension: 22 x 22 x 23. Chair Weight: 10 lbs. Weight: 6.5 lbs