Features: The performance of this module is stable and precise measure of distance. Module precision, blind spots (2cm) super close. High precision up to 0.3cm, detection range is 2cm-450cm, induction angle is not more than 15 degree. This module can be provided ranging program: C51, PIC18F877, ultrasonic LCD1602 display, ultrasonic LCD12864 display, digital tube display, serial display, ranging reference procedures. Simple to use, IO trigger ranging to at least 10us high signal. Module automatically sends eight 40kHz square wave, automatically detect whether a signal return. A signal to return to a high IO output, high duration of the ultrasonic time from launch to return.