MEASURE TO FIT: It is highly recommended to take measurements of your existing foam mattress core to ensure a proper fit with the dog bed cover; for additional sizing information, please see the product details below GIVING YOU OPTIONS: You can also use alternative bed fillings such as old clothes, shredded foam, beanbag beads, buckwheat hulls, or feathers; PRODUCT DETAILS: Dark Sage; Jumbo Plus, designed to fit 53" x 40" x 5" foam mattress EASY CARE: The dog bed cover is completely machine washable for your convenience; for more specific washing instructions.