A little disappointed with this purchase. As a product it is effective at extraction, which is good, however the noise, while not particularly loud, sounds bery rough. The instructions that come with it for fitting are possibly the worst I have ever encountered and ultimately impossible to follow as suggested. In the end to fit the two piece chimney I had to resort to duct tape as the screw holes were impossible to access. The AO service, as ever was great but sadly the product not so.