This rooftop exhaust vent cap is designed to be used with bathroom and kitchen exhaust venting systems. This is a roof mounted vent cap that comes with a damper to prevent back draft, and also with a screen to keep out insects and birds. This product is made with heavy-duty copper. It also comes in a variety of sizes to fit pipes ranging from 4-inch up to 10-inch diameter. This model contains a metal bottom extension for connecting to flex tubing.