UPCs original half-pound open-cell foam. A no-mix, no-fuss formula that provides consistent, high-quality performance. Insulates and seals all cracks, gaps and voids with a seamless, custom-fit insulation. Unlike traditional factory-made insulation products, UPC 500 will not lose its shape or thermal-resistance performance over time. A cost-effective, air-impermeable insulation solution for residential, commercial and institutional applications.