Duratech Roof Windows Blackout Blinds. These MultiFit roof window blinds are design to fit Velux, Fakro, Duratech Roof Windows and Keylite Windows and are available in white, beige and navy blue. They have a chrome finish and are available at an affordable price. View and buy the full range at www.jjroofingsupplies.co.uk. All blinds are available for national next day delivery.