Consistent fragrance release. The fan turns sparingly in week 1, and gradually turns more frequently until week 4 then it runs continuously. The cover is the air freshener. Days 1-29: green LED flashes indicatting 'all systems go'. Days 30+ : red LED flashes indicatting 'time to change cover'. Day 33+ : red LED flashes plus audible alert sounds every 3.5 minutes if the over is not changed.
