Slim magnetic contact via bidirectional radio, frequency 868Mhz. EN50131 Grade 2 certified. The RWX73M 2-Way Wireless Magnetic Door/Window Contact is an ideal supervised transmitter for wireless door/window protection in residential and small business applications. The transmitter has a built-in magnetic contact and an additional zone input, to which other magnetic contacts or wired detectors can be connected, which can be used for different control or security applications. CR123 3V lithium battery included. Compatible with RISCO™ Agility 3 system.