Metal insulation Fixings are made of carbon steel,pre-galvanized sheet or stainless steel.It is more suitable to install and fix the rigid insulation boards onto the masonry, concrete or brick walls. The anchoring and fixing strength is stronger than plastic insulation plugs.During installation,directly drill through the insulation layer and enter the base materials and hammer it into the insulation board to fix it firmly.Designed 35 mm head and 8 mm body outer diameter with various length.