GREAT STUFF Fireblock Insulating Foam Sealant is a ready-to-use, minimal-expansion insulating foam sealant that fills and insulates gaps up to 3/4 inch to restrict airflow. This distinctly orange solution seals electrical wiring run through wall studs as well as service penetrations in walls and between floors to provide a simple, cost-effective way to maintain the continuity of an approved fire block material throughout the house. Expands to fills, seals, and insulates gaps up to 3/4 inch Adheres to wood, metal, masonry, glass and most plastics Impedes spread of fire and smoke through service penetrations Tested according to ASTM E84, ASTM E814 (modified), UL 1715 Seals service penetrations between floors Seals electrical runs through wall studs Forms a long-lasting, airtight and water-resistant barrier Tack-free in 5-15 minutes3; trimmable in one hour Orange-colored foam for easy identification and inspection Cures rigid in 8 hours All-direction dispensing UL classified