... Size:80mm--250mm Material:galvanized steel Color:RAL9010.RAL9016 exhaust air valves are designed for installation on the ceiling or in a ... ,- Made of zinc-coated steel,- Painted white (RAL 9010),- Easy air flow adjustment by turning the central part,- The blocking nut ... low noise level,- High quality finishing and modern design,- These valves can be installed directly on a duct,- Quick and easy ...