This ultrasonic sensor uses the exact same Arduino library as the HC-SR04. This sensor was originally designed to be installed in a vehicle as a parking sensor. The ultrasonic transducer is waterproof. 

Specifications:

• Operating voltage: DC 5V
• Current: 40mA
• Acoustic emission frequency: 40khz
• Max distance: 4.5m
• Blindspot: up to 25cm
• 70 degree detection angle
• Recommended installation hole: 20mm diameter
• Sensor Cable length: 2m

Wiring: 

• + 5VDC
• Trigger
• Echo
• GND

Package Includes:

1 x DC 5V Waterproof Ultrasonic Module and Transducer