Up to 90 days (45 days each refill on low). Eliminates lingering odors. Up to 2X odor eliminating power (vs. base Febreze). With OdorClear. Febreze odor elimination technology. For use with P&G air fresheners SY-982 and 4E-100. Questions? 1-800-699-4657. www.febreze.com. www.pg.com. Good Housekeeping: Since 1909. Limited warranty to consumers. Replacement or refund if defective.