Plastic Circular In-line Back Draught Shutter – 100mm
Alpha Air Ventilation Supplies
£3.05
Back-draught shutter for plastic ventilation ducting lightweight gravity flaps close when the fan is off to keep out draughts, cold air and fumes. 100mm in-line back draught shutter for round plastic ducting a rigid plastic fitting with lightweight gravity flaps that open with the airflow when the fan runs, then drop closed when it stops. Fitted in-line within a 100mm duct run, it keeps out cold draughts, backflow and outside odours without restricting extract performance. Back draught shutters are a simple upgrade for any extract system: they stop chilly air blowing back through a bathroom fa
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