Extractor Fan 100mm In-line Back Draught for 4 Inch Ducting
Back Draught Shutter Vent
For 4 Inch (100mm) Extractor Fan Ducting
In-line spring operated back draught shutter.
Stops back draught and wind noise when a fan is switched off.
Made from tough, white GRP plastic.
Fits Inside standard size 100mm diameter ducting.
Fit the shutter with the centre spindle of the flaps in a vertical position and make sure ducting is level.
Other ducting products availabe in our shop.
Please note that these shutters have 1 spring and not 2.
This is correct as 2 springs would offer too much resistance.
Complies with Part F building regulations.
Suitable for commercial and domestic use.