The Cold Weather Door Covers are designed to attach to the Powder Coated Steel Wire Doors of our Kennels. The Cold Weather Door Covers will keep 90% of the cold air out of the dog compartment. Kit includes 2 cold weather door covers and needed hardware and instructions. Size small will fit the kennel for small trucks (CMDUECE), large will fit the kennel for large trucks (CMDBOX), and extra-large will fit EZ-XL Kennel (NLC2101).