Rtul provides ultrasonic flaw detectors includes models 4400 a and 4400 m. These detectors are designed to detect internal flaws such as cracks, and blow holes. They can also be used to find out elastic constant and correlating sonic velocity to mechanical parameters. It is applicable to diverse areas like: casting, forging and rolled products; weld inspection; bond testing; automatic immersion testing of tubes and rods; research and laboratory studies. The basic advantages associated with these models are they are light in weight, portable, and are battery operated.