Thomas & Betts DX-5 DUCT SEAL COMPOUND (5 LBS)

The DX-5 duct seal compound holds from -40 to 250 degrees F, so it works in unconditioned attics, rooftop penetrations, and outdoor conduit hubs as well as inside a mechanical room. That range covers most exterior service entrance and meter socket sealing work in cold climates.

No, and the distinction matters on an inspected job. The DX-5 is a duct sealing compound for air, moisture, and pest infiltration. Firestopping a rated wall or floor penetration requires a product tested and listed for that assembly. Use duct seal for weatherproofing conduit and duct openings, and specify a listed firestop system where a fire rating is involved.

Duct seal is a non-hardening putty. The DX-5 compound stays pliable across its rated -40 to 250 degrees F service range, which is the point of it: you can press it into a conduit end or a wall penetration, and pull it back out later to add a conductor without cutting or drilling. If you need something that cures rigid, duct seal is the wrong material.

It is a duct sealing compound, used to plug conduit ends, wall and floor penetrations, meter socket hubs, and service entrance openings against air, moisture, dust, and pests. Press it in by hand, no tools or mixing. It is a chemical product, not a mechanical fitting, so it fills irregular gaps that a bushing or grommet cannot.