Vent Systems 4" Inch Round Roof Vent Cap Galvanized Metal for All Weather Conditions Top Round Exhaust Cap with Rubber for Perfect Insulation Vent Cover - Chimney Cap 100 mm - Amazon.com
Hon&Guan 6 Inch Removable Roof Vents Roof Dryer Vent Cap for Houses Galvanized Steel 6 Inch Exhaust Vent for Ventilation System-with Damper, Black. - Amazon.com
Vetnline V0507-02 Roof Cap with Slant Flange
Broan-Nutone 3 In. or 4 In. Black Steel Roof Vent Cap - Bliffert Lumber and Hardware