This is the US-100 Ultrasonic Sensor Distance Measuring Module with Temperature Compensation. The US-100 Ultrasonic Sensor can measure or detect

This ultrasonic sensor is very similar to the ultrasonic sensors which are found in cars. This Waterproof Ultrasonic Obstacle Sensor

This SHARP distance sensor bounces IR off objects to determine how far away they are. It returns an analog voltage

Ultrasonic Distance Sensor provides very short (2CM) to long-range (4M) detection and ranging. The sensor provides precise and stable non-contact