air valve,air damper Size:80mm-1600mm Material:Stainless steel Galvanized steel Tpye:Handy or Electric air valve,air damperSize:80mm-1600mmMaterial:Stainless steel Galvanized steelTpye ... duct and accessories production lines Products are widely used in air conditioning, airports, shipbuilding, exhibition, Coliseum .,etd air damper/air valve