High sensitivity vibration switch SW-18010P. It also includes aLM393 wide voltage comparator to clean signal.The 4 pins are Vcc (3-5VDC), GROUND, DO (Digital Out), and AO (Analog Out).Using the AO pin a voltage proportional to the vibration intensity can be read from an Arduino analog input. Using the DO pin, the potentiometer adjusts the set point. If the vibration exceeds the set point the DO level goes LOW.SpecificationsFixed bolt hole for easy installationPCB size: 15×30 mm aproxIt use LM393voltage comparator