Features: Touch screen, long press to open/close, bring you a good experience. S7 waterproof, 12-hour and 24-hour switching, maximum timer 999 seconds. 4-in-1 multifunctional meter, equipped with a timer, air or water thermometer, voltage meter. Small and compact, unique appearance, easy operation. High quality material, never flash, waterproof, high accuracy. High water temperature/low voltage alarm. The default value of low voltage alarm is 11.5 and the default high value of temperature alarm is 75℃, which can be set by yourself. Specifications: Material: PC Voltage: 9-24V Dia: Approx. 4.7cm/1.85in Type: Air Temperature/Water Temperature (Optional) Package Included: 1 Set Voltmeter Thermometer Note: The water temperature type needs to be connected with a special water temperature sensor. The red wire connected to the positive pole, the white wire connected to the negative pole and the blue wire connected to the electric door lock.