Usage Tips:Features: 1.Multi reminding methods (need to use with host + camera, not included). When an abnormality is detected, the door sensor alarm will send a signal to the host, and the host will alarm loudly, and automatically call/send alarm messages, and the scene can be checked through the camera. 2.High-quality craftsmanship, the appearance of the use of anti-UV materials, to ensure that the sensor does not fade for a long time, for safer use, high-quality flame retardant materials are selected. 3.The pocket door and window sensor has a mini body, does not take up space, it is perfectly integrated into your home environment, and will not affect the aesthetics of the home style. 4.Tool?free installation, just stick and use. It will not be incompatible with the home decoration. It can also be pasted to drawers, cabinets and letter boxes. Just tear off the protective film on the double?sided tape and paste it. 5.Built-in 1pc CR2450 button battery, standby current 20uA, alarm current 50mA, low power consumption, long useable time, and long-term protection for your home safety. Specification: Item Type: Door Magnetic Sensor Material: ABS Supply Voltage: 3V Power Supply Mode: Button battery 1 x CR2450 (Include battery) Standby Current: 20uA Alarm Current: 50mA Wireless Frequency: 433MHz Wireless Distance: 100 meters/109yd (barrier-free) PackageList: 4 xDoor Magnetic Sensor2 x Adhesive Tape