38x48x6 Large Mattress Cover for Pet Bed This cover slips easily onto Top Paw orthopedic mattresses; instantly providing a softer and more comfortable surface for your dog. Zipper closure. It is machine washable for easy care as well. Cover only, mattress not included. Sized for a 38x48x6 bed. I have dark blue, grey and light blue. Random color will be sent. You can also stuff these with towels and old clothing to make a custom bed for your cat or dog.