Automatic operation, sleek, slim design, excellent performance (one unit delivers the right fragrance for 168 m³ of room), adjustable time interval between doses: 7.5 - 15 - 30 minutes, adjustable mode: day, night or day and night. Easy to operate, with audible alarm for low battery and low aerosol, works with 2 R14 "C" batteries (not included), replaceable fragrance cartridge available in different fragrances, opens with system key.