Dundas Jafine BPGH4BZW6 ProGard 4-Inch Exhaust Hood, Brown 3 Louver damper system helps prevent cold air, snow or rain from entering the home Louvers have been designed to prevent them from sticking Recessed caulk line to assist in a clean caulking application; J-Channel compatible Features a low profile pest guard that helps to keep pests out and can be easily removed to allow for cleaning of the duct UV resistant coating to prevent the cap from discoloring; Paintable