The Cygnus Underwater is the original diver held subsea multiple echo Ultrasonic Thickness Gage. It was designed for use by divers undertaking subsea maintenance and surveys 3 decades ago? and today it is still the industry standard.
The unit is depth rated to 1,000 ft (300 meters) and it provides an accurate metal thickness measurement through coatings up to 0.787″ (20 mm) thick. The bright LED display ensures easy viewing even in poor visibility conditions.