HVAC Ventilation Volume Control Adjustable Manual Air Duct Valve Fire Smoke Volume Control Damper fire valve. Low air leakage and good air tightness,the electric switch consumes less current.Strong corrosion resistance and long service life, beautiful appearance and good ventilation.
Read MoreSend InquiryChina manufacturer high quality galvanized steel square rectangular common flange flexible duct. The common flange flexible duct has low resistance,high density, good feature of compression strength, fire-proof performance better than steel plate,oxygen index 100, non-burning Grade A.
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