Rosewood 40 Winks Tough & Mucky Mattress. Mattress/sleeper for dogs. Double-sided design with colours which work with most colours of plastic bed. Fits the Sonny plastic beds perfectly, but can also be used as a standalone sleeper. Water-resistant, but soft, fabric: easy to wipe off mud or pet hair; plus resists rips and tears. Simply wipe clean or machine washable at 30 degrees.