Vibrating Mesh Technology is a mesh/membrane with numerous laser cut holes that vibrate and pressures out a very fine mist of premium fragrance. Contains no aerosols or propellents and are not pressurized. Can be programmed to work to suit venues opening times, and matched to location conditions. With up to 3x less refills per year than other aircare systems. Delivers a consistent fragrance over the life of 30/48/60 or 90 days, no matter the location. Uses 4 "D" cell batteries.