The Timewick Unit is a passive odour dispensing unit that requires no power source. It will deliver up to 60 days of consistent air freshening. The timewick works by releasing essential oils from the cartridge at an even rate into the air, providing a fresh clean scent that is not over powering. The cartridge is locked into place upon inserting, making it tamper resistant. One unit will work in areas of up to 2,500 square feet. For a limited time this item is being sold as a complete kit which includes one dispenser and one cartridge.