(2)OMG CR Base Sheet Fasteners are one-piece, precision formed from G-90 galvanized steel, coated with CR-10, and pre-assembled with a 2.75in. diameter galvalume plate. These fasteners are designed to secure base sheets to poured lightweight insulating concrete. The 1.2 CR Base Sheet Fastener can also be used on certain poured gypsum decks. Available Sizes: