Three sides louvered for greater air flow. Large nailing flange. Heavy-duty galvanized steel construction. Fits all pitched roofs. Weathertight seamed collar. High profile for increased weather protection and circulation. Prevents roof discoloration. Birdproof. 50 sq-in of net-free ventilating area. 16 in x 20-5/16 in x 5 in overall size.
