Looking for an air freshener containing twice as much fragrance as most other air fresheners which is released over 30 days? Easy to use, simply replace the old cover with a fresh one - it's easy! No aerosol, just a fragrant cover which lasts 30 days. No keys or tools required. Magic eye setting turns fan off when the lights go off allowing battery to last up to 4 months. Intelligent fan is programmed to increase the amount of time it works in order to give a consistent amount of fragrance over 30 days. LED reminder when the cover needs changing.