The Gauge offers you greater mobility when measuring: used in conjunction with your smartphone or tablet, 549i high-pressure measuring instrument is suitable for carrying out wireless servicing and troubleshooting on air conditioning and refrigeration systems, as well as for installing them. The measuring instrument can be set up quickly and easily, directly at the pressure connection. The 549i makes working on widely spaced pressure connections considerably easier thanks to wireless connection to a smartphone or tablet. Also practical: no hoses are required for measurements, meaning that no or only very little refrigerant is lost. When used in conjunction with the 115i clamp thermometer, individual refrigeration system parameters can also be calculated. More measuring convenience thanks to the App, Readings can be viewed conveniently on your terminal device via the Smart Probes App. The App also enables evaporation and condensation temperatures to be calculated automatically. All measurement data is displayed either as a chart or in table form. The measurement data log can be emailed directly as a PDF or Excel file. System requirements: iOS 8.3 or later Android 4.3 or later Bluetooth-compatible 4.0 Max Measuring Range: 200 PSI & Above Dial Diameter:1.9 Inches & Under Display Type:Digital Colour:Yellow Material:ABS+Metal Package Contents: 1 x Pressure Gauge 1 x English manual 1 x rope Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.