alarm: This infrared alarm is designed with function, which can automatically detect the movement of the person. Convenient and portable: The infrared motion sensor detector is small and , easy to carry, and can be placed in a pocket or backpack. Reliable quality: The infrared alarm is made of high-quality abs material, which is durable and has a long service life. REASONS TO BUY: Wireless infrared motion detector: with wireless infrared motion sensor, you can easily identify the location of your home and office. it also has a remote control function to detect small objects such as cars, boats, motorcycles, etc. Reliable quality: the infrared alarm is made of high-quality abs material, which is durable and has a long service life. alarm: this infrared alarm is designed with function, which can automatically detect the movement of the person. Convenient and portable: the infrared motion sensor detector is small and , easy to carry, and can be placed in a pocket or backpack. BUYER SAYS: I tried and it really works value for money. of use 3 button batteries (LR44); Pull the alarm lever to trigger the alarm; Press the return lever to stop the alarm; The cover of this product slides downward, and there are "OFF" and "AUTO" keys on the right side. AUTO stands for start of infrared alarm system; OFF means the infrared alarm function is OFF. (1) place the product on a vibration-free, dry, flat surface within three meters of the area to be monitored. (2) move the "slide" down. (3) slide the "off /auto" switch to auto, and the product will enter the alert state. After 35 seconds, if the movement is detected in the covered area, the alarm will sound for 15 seconds, and then automatically reset to enter thealert state again. Colour:As Shown Material:plastic Package Contents: 1 x Infrared Motion Sensor 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.