The Cigar Oasis Ultra electronic cigar humidifier was designed to mount on the lid of the humidor (or on or under a tray) with minimum space requirements. It uses an upgraded microprocessor technology to measure and control the humidity accurately. It has two modes of control. When used with battery power it works until the desired humidity is reached. Then the unit goes to ‘sleep’ which means the power is turned off to extend battery life. It will sample the humidity every five minutes to make sure the humidity is correct. If not, it goes into control mode to adjust humidity. When operating on line power it samples the humidity continuously. In both cases the control point is set to 70% humidity. The unit comes with a sealed water cartridge mounted and ready to use.