Ultrasonic Module HC-SR04 Distance Measuring Transducer Sensor Compatible With Arduino by Atomic Market Using IO trigger for at least 10us high level signal. Static Current(Max) : 2mA ;Electrical Level Output : 5V High Detection Distance : 2cm-450cm;High Precision: : 2mm. Automatically sends eight 40 kHz and detect whether there is a pulse signal back HIgh Quality Atomic Market Product