DL Wholesale Thermal IR Blocker, 4' x 50'DL Wholesale Thermal IR Blocker This revolutionary NASA developed material will reduce thermal imaging heat signatures by 97%. Each layer of material is bonded to polyurethane for strength and durability and has a inner layer of insulation to prevent conductive heat flow. Available in 3 sizes 4 ft. x 25 ft. 4 ft. x 50 ft. 4 ft. x 100 ft.