To ensure your pet’s safety, regularly check all kennel parts and doors for replacement. This Replacement Vent is designed specifically for use with the Indigo Dog House Sizes: MED (37.5″ x 30.5″ x 22.8″), LG (43.75″ x 34″ x 25.8″) and XL (51.5″ x 39.3″ x 30″). To ensure a proper fit, be sure to match your pet’s shelter size with the appropriate product/item number for this replacement vent. Does not include hardware. Use original hardware that came with the dog house.