All natural sheepskin is the preferred surface for pressure ulcer prevention. This machine-washable sheepskin mattress pad is made of 100% wool to provide ultimate user comfort, while protecting the skin from deteriorating and becoming infected. This sheepskin mattress topper is very easy to use and maintain. All natural medical sheepskin pads vary slightly in size, but average 8-9 sq. ft. (about 36" x 36").