The JSN-SR04T is an easy to use waterproof ultrasonic distance sensor with a range of 25 to 450 cm. If you are planning to build a water level measuring system or if you need to take other distance measurements outside, then this is the sensor you need!
The HC-SR04 is an inexpensive, easy to use distance sensor, with a range of 2 to 400cm. It is commonly used in obstacle avoiding robots and automation projects. Did you know that your car uses similar sensors in the parking assist system?