It works with any home or commercial machine using 120V or 240V solenoid valves. The shot timer works by detecting the start of a shot with a magnetic sensor that mounts on a group’s brewing solenoid. Installing the sensor takes minutes and requires no modification to the espresso machine. The shot timer runs on a standard coin cell (CR2032) battery for up to 4 years and has been tested to handle the heat and humidity of a busy café environment.