Amerimax 85080 Ridge Vent, 10.5" X 20' Size : 10.5" x 20' Keeps attic dry deterring growth of mold and mildew. Prevents rot and structural degradation made of recycled post industrial fiber. No maintenance or operating cost ul class a fire rating eliminates unsightly fans and vents. Protects roof and shingles from damage due to excessive heat or condensation grips to roof and installs quickly