1-3/4" Anchor Plate Assembled with 3” Zinc Wood Screw for attaching Insulation Boards. 1000 pcs. box 8 x 3" Yellow Zinc Coarse Thread Screw Insulation Thickness: 2-1/2" Insulation Used For: The mechanical attachment of Expanded & Extruded Polystyrene Insulation Board (EPS or XEPS) to any screwable wood sheathing or siding. Other uses include the attachment of Stucco Mesh, Expanded Wire Lath and Fiberglass Fabrics over rigid insulation boards.