This BBL board is made out of Polystyrene, it is breathable and firm. The curved design can provide an even compression and create a soft barrier over your skin to reduce bruising and swelling, and keep your lumbar area smooth and flat. Also, this backboard is ergonomic, it is an invisible abdominal Ab board under the compression garments and won't attract anyone's attention. So you can wear it wherever you stay at home or go out. Width: 8.9 inches, High: 5.8 inches.