Me PIR sensor from Makeblock is used to detect motion from animals/humans from about 6m away. If anyone moved in that range, the sensor outputs HIGH on its SIG pin. With a potentiometersoldered on its circuit board, you can adjust its detecting range according to your need. Here are some ideas for application: motion detecting, thief-guarding system, automation switch. Note: when you give it power supply，you may need to wait 10 seconds until the sensor Initialize. Features: * Adjustable detecting range and high sensity * A power indicator LED(Red) and a state indicator(Blue) * 16mm interval M4 mounting holes, compatible with Makeblock beams * 2.54mmbreakout pins for connecting with jumper wires * Easy wiring with 6 Pin RJ11 interface * Arduino library for easy programming