5/16" thick with two outer layers of aluminum foil. Each foil layer is bonded to a tough layer of polyethylene for strength. Reflects up to 97% of radiant heat with an R-value up to 14.3 depending on application. Excellent vapor barrier for below grade. Can be used for radiant floors, crawl spaces,...

Extra hard bit engineered for high torque. Forged tip reduces breakage. Torsion zone absorbs torque peaks to reduce stress. Hardened core increases bit strength, reduces fractures. Engineered to meet ISO standards.