This rugged Amerex fire extinguisher uses carbon dioxide to smother fires by displacing oxygen and leaves no residue behind. Discharged as a cloud of "snow," carbon dioxide Is a clean, non-contaminating, odorless gas. The extinguisher has a 5-lb. capacity and features all-metal valve construction and rust-free cyclinders to ensure a long life. Meets many medical equipment requirements. This extinguisher has a UL rating of 5B:C and a five-year manufacturer's warranty.