Note: It can only work with Chuango 315MHz G5/A11/B11/H4 Plus alarm system, cant work with 433MHz alarm system. The DWC-102 works well with any door, window or opening. When triggered (separated), an alarm signal will be sent to the system controller for appropriate response. If connected to a GSM alarm system, low-battery alerts via SMS text messages are possible. Features: *Low-consumption chip design, which can make it work long time. *High Sensitivity. Excellent design, tiny and fashion. *It also comes with tamper protection to ensure system integrity. *Simply attach one piece to your door or window, and attach the other piece to the door or window frame. *Ideal intrusion warning for homes, apartments, mobile homes, dorms, offices, ho rooms, garages, etc. Specifications: Power supply: DC 1.5V (AA 1.5V LR6 Battery x 1 pc) Static current: ≤35uA Alarm current: ≤10mA Transmitting distance: ≤80m (in open area) Radio frequency: 315MHz Housing material: ABS plastic Operation Condition: Temperature: -10°C~55°C Relative humidity: ≤80%(non-condensing) Item Size: 71 x 34 x 17.5mm (L * W * H) Package Size: Approx. 16 * 11 * 5cm / 6.3 * 4.3 * 2in Package Weight: Approx. 130g / 4.6oz  Package List: 1 * 315Mhz Door Sensor