Four J Weatherization Windows, Insulation, Energy Savings Installed into pre-existing walls. Superior air sealing at an affordable price. Cellulose insulation is made from recycled paper combined with borax to make it fire and pest resistant. Dense packing also provides an acoustical barrier, reducing outside noise. Blown into attics, fiberglass provides the top quality insulation and better coverage than traditional batt insulation. By slowing down the transfer of heat through the attic, heaters and air conditioners do not need to work as hard to maintain a constant temperature inside of the house. Made with Xara Cellulose Fiberglass