Backdraft shutters did not fit in manrose fan rebate. Shutter didn't close every time fan went off, as springs are not strong enough, I put stick on weights which has helped, Shutters flap and make alot of noise!!
Seem expensive for what they are,!!!
It does what it says on the tin, stops back draughts through a bathroom extract fan and also fits perfectly within the 200mm diameter extract pipe.
Cheaply made wouldn’t purchase again
Not convinced I really needed this part but it fitted with ease and along with replacement fan works a treat
Simple product did the job