Reminds you when to change it, simply pull off the date tabs upon installation to remind you when to change the air freshener, it's easy! Includes 1 "screen saver" bag per box to store spare screen until needed. Freshen urinal a full 30 days. Contains more than twice as much fragrance as 'look-alike' screens. Releases billions of optimized bacteria that clean the urinal and eliminate odors. Longer protrusions on top release fragrance and reduces splashback.