Motorised damper 1.Material: galvanised steel 2.Insulation outside 3 ... 200,250,300,350,400,450mm 4.Lowest price Mottorised damper ,air condition parts,damperDuct installationMaterial :Galvanised steel 0. ... 0.8mm as required,but cost penaltyThere is one damper inside the body to stop the air in the ... in one carton box ,8pcs packed in to one big carton boxWe, with 500 people, several distributions, have ...