MittShells Extra-Dense Memory Foam Pressure Relief Seat Cushion,for Office Chair. Pressure Relief: Extra-dense memory foam cushion contours to your body, relieving pressure on the hips, tailbone, coccyx, and sciatic nerve. Ergonomic Design: Ideal for long periods of sitting at the office, home, car, or wheelchair, promoting proper posture and spinal alignment. Durable Construction: Resilient high-density foam resists compression, maintaining its shape and support over time. Versatile Application: Suitable for various seating surfaces, including office chairs, home chairs, car seats, and wheelchairs. Easy Maintenance: Removable, machine-washable velour cover ensures lasting freshness and cleanliness.