Square Tailbone Cushion: Pressure relief, comfortable and breathable, making you fall in love with the feeling of sitting. Suitable for elderly people, long term bedridden individuals, or those sitting in the office for extended periods of time. Breathable Fabric: The Donut Cushion is made of honeycomb breathable fabric, which is easy to take care of, easy to clean, and can be used all year round. Smooth surface can be used in hot weather. Not Easy to Deform: The Seat Cushion features a high rebound hollow cotton core that stays in place for long periods of time, with a 360 degree circular support that fits the human body. Ergonomic Design: Butt Cushion, with an outer square and inner circle, in line with ergonomics. The inner ring shape is designed specifically for the buttocks, making it comfortable to use. Zipper Design: The Sitting Pad adopts a zipper design, which is easy to disassemble and finely crafted. Size Chart: Style A: 43cmx43cm/16.93inchx16.93inch, inner diameter: 20cm/7.87inch Style B: 37cmx37cm/14.57inchx14.57inch, inner diameter: 17cm/6.69inch Package Includes: 1xSeat Cushion Note: Please allow slightly errors due to manual measurement and different monitors.