It works well, there’s something wrong with the backlight as pictured on the screen.

The Testo 550S Smart Vacuum Kit is the perfect solution for those looking to charge, temperature, vacuum, and pressure gauge purposes. This kit includes a blue low side hose, red high side hose, and yellow service hose, and is compatible with a variety of refrigerants such as R-409a, R-500, R-1234yf, R-502, R-513a, R-600a, R-123, R-134a, R-290, R-410a, R-401b, R-401a, R-12, R-414b, R-507, R-407c, R-416a, and R-22. The kit also features wireless and digital capabilities, making it a convenient and efficient tool for HVAC and refrigeration applications.