The poor man"s accelerometer/motion sensor! These spring-vibration switches are high sensitivity non-directional vibration induced trigger switches. Inside is a very soft spring coiled around a long metal pin. When the switch is moved, the spring touches the center pole to make contact. So, when there"s motion, the two pins will act like a closed switch. When everything is still, the switch is open. Great for basic projects and wearables! We also have a version with a stiffer spring, which is harder to trigger!...