Effectively monitor the movement of the human body in a variety of environments with sensitive, accurate reporting and anti-jamming technology. Easy installation with wireless detector and receiver separated. Just place the sensor at the entrance and place the receiver anywhere you need. Send audible chime sound, alerting you that somebody is approaching. Used as visitor reminder or anti-theft alarm in store, home, office and factory. Key Words: automatic, door guard, motion sensor, alarm, store Specification: Power: sensor 9V battery/receiver 2 AA battery (not included) Transmitter Size (L x W x H): Approx. 3.5 x 2.4 x 1.8 inch Receiver Size (L x W x H): Approx. 3.5 x 2.6 x 1 inch Receiver Switch Setting: High / low volume / off Material: Plastic Operation Instruction: The product is stable and reliable with IR motion sensor and high quality electronic components. It has two functions-visitor reminder and anti-theft alarm. You can choose either function as you need. The detective distance is beyond 10 meters and the valid distance between detector and receiver is beyond 200 meters in open space. The receiver requires 2x AA battery and the detector requires 1x AAA battery (batteries not included). When used as visitor reminder, the item should be installed on the top of the door or on the wall with the detector adjusted to the suitable position. The receiver will ring automatically when visitors come into the detective distance. Attention: The product will do a ”self-check” for 10 minutes when it turns on. Them it comes to work. Please do not install the detector in the place where there is changeable air flow or heat like Air vent, exhaust fan port, electric furnace or heating surroundings. Keep it away from sunlight, rain and metal. If the product fails to work please check or change the battery in the detector. It is normal that the detective di