【Excellent Design】This is a pair of infrared detectors including the transmitter and receiver to enable automatic sensing of ambient changes and when the beam being bothered, it alarms you. 【Practical Use】There are dual beams for quick speed respond. With premium shell, it is waterproof for practical use. 【Warning Distance】It is an intelligent item and its alarm distance up to 100m in outdoor environment. Optical lens up and down while structural adjustments, to adjust faster and more accurately. 【Low Power Consumption】The transmit power will be adjusted automatically according to the environmental conditions, which greatly extends the life of the launching tube, while lowering power consumption. 【Smart Alarm Technology】Professional chips and strong anti-interference provide smart detection alarm technology to modern life.