0563 1550 Digital Thermometer, 2 Input Handheld. The testo 550 instantly displays superheat and sub-cooling for up to 60 refrigerants. It also measures high / low side pressures and temperatures. With its Bluetooth linked App, the testo 550 opens up new possibilities for efficient analysis and documentation. Its versatility includes 60 refrigerant profiles and added functionality for leak tests. The rugged instrument housing includes a metal frame around the display which protects the digital manifold from impact. Users can view measurement data on Smartphone or Tablet, enabling quick and convenient completion and documention.