12 GA (0.105"), mild steel Galvanized pin and plate Made in America with high quality materials Use with Boss 180 Multi-Seal Insulation Anchor Pin Adhesive. Self-locking washers and dome caps are sold seperately Made in USA Used to support rigid board and batt type insulation on wall and ceiling applications. The anchors incorporate a 12-gauge spindle (nail) and a 2" x 2" square perforated base made of low carbon steel, galvanized coated. Perforated Insulation Hangers are also great for installing fiberglass board panels onto ceilings. Simply glue/screw/nail the base of the insulation fasteners to the ceiling, pierce the fiberglass panel onto the pins (1 pin on each corner minimum) and push the washer onto the pin to hold the panel in place. Snip off the remaining part of the pin if necessary. You can also spray paint the washers the color of your fabric to help blend the washers with the fabric.