CRC Minimal Expansion Foam is the simple way to fill, seal, bond, retrofit, insulate and deaden sound in and around cavities. The UL Classified, polyurethane foam forms a permanent, waterproof and airtight bond to masonry, wood, glass, metal and most plastics. It stops drafts, dust, moisture, insects and rodents. Minimal Expansion Foam cures to a semi-rigid, closed cell foam that insulates to R-5 for each inch of foam. It uses a non-flammable propellant and a 360? valve for safe and accurate dispensing. Minimal Expansion Foam is also reusable for up to 30 days after initial use.