INSTEON Door/Window Sensor
By Insteon (2843-222)
MCM Part #82-19910
INSTEON Wireless Magnetic Contact Switch
The INSTEON Wireless Open/Close Sensor is a magnetic contact sensor that wirelessly controls lights and appliances throughout your house via RF technology.You can program any INSTEON device (available separately) to react to the magnetic contact sensor, and you can optionally connect an external contact closure sensor of any type (e.g., hidden contacts or doorbell button; not included).
The sensor works on a single AA battery (included). It stores all of its settings, such as links to other INSTEON devices, on a non-volatile memory, so they will not be lost when the battery is removed.