Motor-driven fan moves fragrance further than a typical passive system, Powerful enough to freshen even your largest spaces, Easy to refill air freshener dispenser uses the fragranced cover of the dispenser as the air freshener refill itself, Smart system provides consistent freshness over 30 days by turning the fan sparingly in week one, and gradually turning it more frequently until week four when the fan runs constantly, Handy light alerts you to change your cover after 30 days, Use with the Easy Fresh refills with battery