Dometic 3311236.000 Cap and Base Vent Kit USE - Mounts to the roof of your RV above refer. This allows circulation and the heat created by the refer to be released DIMENSIONS - Bottom Flange Overall: 25-7/8"" L x 8-1/4"" W Top: 23"" L x 6-3/4"" W Base Sits 3-5/8"" H Overall Mounting Holes for Cap Spaced: 21-7/8"" L x 5-3/8"" W Cap -Overall: 26-5/8"" L x 11-1/4"" W Cap sits 3-7/8"" H Mounting Holes Spaced: 21-7/8"" L x 5-3/8"" W" COLOR - White. Screws not included.