QT Tornado is the compact maintenance tool for odors in areas up to 40,000 cu/ft. Designed with a multi-option timer and variable ozone control, this powerful little unit can adjust to almost any situation. IMPORTANT: OZONE IN HIGH LEVELS IS NOT RECOMMENDED FOR OCCUPIED AREAS. This Is The Recommended Unit For Hotels, Condo Owner, Multi-Housing, Etc. All Queenaire Models Have A 5 Year Warranty, 15-20 Year Life Expectancy.