It's a new type of nanotechnology air freshener dispensing system that works With unique Air Fresh and Air Clean refills. This programmable unit Features: LCD w/Real time clock, 5 or 7 day On/Off selection, 1-60minute spray interval setting, customized Start & Stop time, Spray counter, Empty can reminder (12,000 sprays), Low battery monitor and operation indicator. With push button design for easy On/Off. With chemical resistance plastics. Operates on 4 C-cell Alkaline batteries. One unit recommended for a room area of 8000 cubic feet. Batteries not included.