Foil Bubble comprised of layers of polyethylene air bubbles sandwiched one layer of 99% pure aluminum foil.ROLL SIZE (W X L)1.2m X 60m BUBBLE SIZE4MM X 10 MM TOTAL THICKNESS (MM)4.5 T0 5 MM REFLECTION RATIO95% THERMAL RESISTANCEEMISSIVITY0.04-0.05 TEMPERATURE RANGE-122 ? to 230 ?(-50 ? ? 110 ?)