Manrose CF100H Centrifugal Extractor Fan 100 mm / 4 Inch (Humidistat) on OnBuy
Xpelair C4HTSR 4" Simply Silent Contour bathroom extractor fan with humidistat and timer, plus choice of square and round baffles, White, 240V : Amazon.co.uk: Home & Kitchen
Envirovent Silent-100 SIL100HT Silent Extractor Fan with Humidistat Timer