Three sides louvered for greater air flow. Large nailing flange. All-aluminum, rust-free construction. Fits all pitched roofs. Weather-tight seamed collar. High profile for increased weather protection and circulation. Prevents roof discoloration. Bird-proof. A Model 700 with a neoprene damper installed for use as a kitchen/bathroom exhaust is available. 50 square inches of net free ventilating area. 16 in x 20-5/16 in x 5 in overall size. 11-0602.04 Miami Dade County approved.