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. Fireblock insulating foam sealant Reusable for up to 30 days with the Smart Dispenser™ No drip dispensing eliminates mess Easy to use, with greater control Impedes spread of fire and smoke through service penetrations Forms a long-lasting, weathertight seal to minimize drafts Tested according to ASTM E84, ASTM E814 (modified), UL 1715 Seals service penetrations between floors Seals electrical runs through wall studs Tack free in 5-15 minutes 340 g (12 oz) This product is not approved as a Fire-Stop material.