Oliver & Iris 4-Inch Orthopedic Memory Foam Dog Bed, Small, Navy Blue 4 thick mattress made up of: 2 luxury grade memory foam and 2 high density support foam Super soft, upholstery grade microfiber velvet cover is easily removeable and machine washable 100-percent waterproof mattress liner protects against those unfortunate accidents" Great for relieving the symptoms of hip dysplasia, arthritis and joint pains Proudly Made in USA for higher quality and 5-Year Manufacturer Warranty