Greenwood Airvac Lrbks Low Rise Baffle Ventilation Grille Cover (sand) for sale online | eBay
Amazon.co.uk: Greenwood Airvac Extractor Fan
Greenwood Airvac on Twitter: "@Taid50 Hi David, There is a small round cover in the bottom corner just below the word 'airvac'. Remove the small round plastic cover and there should be