Single Sided, Double Sided and Top Fixed Clamps are to be used for 10mm & 20mm Clamp-on Screens, Single Wrap Screens and Double Wrap Screens and made from Steel with a black or white powder coated finish. Desk Hung Screen Brackets are for use on 20mm Single Wrap Desk Hung Screens and 20mm Desk Hung Screens and are made from Black Nylon.