The Cushion: Orvis Memory Foam Orthopedic memory foam supports joints and muscles, relieves pressure points, and improves circulation (especially beneficial for older dogs and larger breeds) Our open-cell foam is a single piece (not chopped foam), and is designed specifically to support a dog's body shape and weight distribution Low-VOC CertiPUR-US-certified foam is made without formaldehyde, phthalates, or heavy metals Hypoallergenic, water-resistant liner keeps the memory foam clean and dry, and unzips for easy removal and washing if your dog has an accident