Oliver & Iris 4-Inch Orthopedic Memory Foam Dog Bed, Medium, Ocean 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 removable 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