- Durable Materials: Base frame built from high quality ABS and environmentally friendly PE for sturdy, stable support. - Office Chair Replacement: Designed to work with a 55cm (21 5/8") yoga ball. Convert your exercise ball into a chair; when you want a workout, simply remove the ball and exercise. - Improves Posture: Provides a comfortable dynamic seating experience with ergonomic back support to help reduce discomfort from long periods of sitting and soothe back pain. - Healthy Exercise Ball Chair: Encourages steady muscle engagement, stimulates blood flow, strengthens core, and improves stability and balance. Suitable for use during pregnancy and labor. Use scenarios - Desk work: Use the ball chair base at your workstation to support posture and reduce fatigue during long work sessions. - Quick workouts: Remove the ball easily for short exercises or stretches between tasks. - Prenatal and labor support: Helps with balance and core engagement during pregnancy and labor.