Black Steel Frame w/ Double Frame Bracing Multi-surface Casters with Durable Nylon 5 Star Base Pneumatic Seat Height Adjustment Supportive Polyurethane Foam Seat and Knee Pads Hard Wearing Black Breathable Fabric Seat and Knee Pad Covers Knee Cushion Measure 16.5′ x 12′ W Optional Back Not Recommended for Users over 6 feet in Height Very nice kneeling chair that is both well priced and functional. Kneeling chairs were designed upon the ergonomic concept ‘A strong back is a healthy back’. By promoting good posture, the chairs strengthen the lower back muscles helping spinal alignment and support. Kneeling chairs are recommended by medical professionals around the world. The chairs have a five year warranty and a maximum weight limit of 280 lbs.