This sensor is a high performance ultrasonic range finder. It is compact and measures an amazingly wide range from 2cm to 4m. This ranger is a perfect for any robotic application, or any other projects requiring accurate ranging information. This sensor can be connected directly to the digital I/O lines of your microcontroller and distance can be measured in time required for traveling of sound signal using simple formula as below.
Distance = (Echo pulse width high time * Sound Velocity(340M/S)/2)  or  Distance in cm = (Echo pulse width high time (in uS)*0.017)
The module works on 5VDC input and also gives a output signal directly for detection of any obstacle up to 5m.

Features:

1) Working Current : 15mA;
2) Working frequency : 40KHz;
3) Output: 0-5V (Output high when obstacle detected in range);
4) Beam Angle : Max 15 degree;
5) Distance : 2cm - 500cm;
6) Accuracy : 0.3cm;
7) Input trigger signal : 10us impulse TTL;
8) Echo signal : PWM signal (time required for sound signal to travel twice between source and obstacle);
9) Size : 45mm*20mm*15 mm;