This ultrasonic sensor is very similar to the ultrasonic sensors which are found in cars. This Waterproof Ultrasonic Obstacle Sensor shows some important constructional advantages over the conventional sensors. It comes in two separate parts one being the transducer which is the sensing element and the other being the control board.
The module is capable of providing information of the objects between the distance range of 250 mm to 4500 mm. The great advantage of using this Waterproof Ultrasonic Obstacle Sensor is you can put the sensing element far away from all the control circuitry.