Features: 1. of temperature, humidity, airflow, dust, noise, light and dark, anti-interference, etc. 2. The transceiver module is a field-shaped signal with a wide coverage and no blind spots. 3. Microwaves have relatively good induction effects during transmission: when used indoors, the effect is better; When used outdoors, there may be a slight decrease in sensing distance or sensitivity due to environmental factors. This is a normal phenomenon, users need not doubt it. About electricity: It is recommended to use a qualified DC regulated power supply, that is, a DC regulated power supply with qualified output voltage, current and ripple factor, otherwise it affect the stability of this product and may cause some abnormalities, such as: false alarm, no alarm, self-start of cycle, etc. About false positives: 1. To the eligibility of the power supply, please refer to the first item. 2. Test to that the product under test does not surround the moving object (sensing range) 3. The power supply initialization time is about 10s-30s. During this period, it is abnormal sensory, which may cause false positive artifacts. 4. During indoor testing, the sensor is sensitive to the surrounding environment and needs to remain stationary, and that cycle step test is performed before of the first sensor signal. When testing outdoor, be sure to pay attention to the dynamic surrounding environment, such as birds. Pedestrians, passing vehicles, etc. 5. The signal current output by the module is very weak. It is easy to cause false alarms through the high power of tube. 6. This product is a housing component and the metal is not easily penetrated, so this product should not be used in metal housings. note:The printing/appearance from batch to batch, but not affect the use Colour:White Material: mixture Package Contents: 1 x Microwave Radar PIR switch Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.