Review on Enhanced Aprvtio Refrigerant Leak Detector: LED Light, Halogen Leak Tester for HVAC Systems (R22 R410A R134A R1234YF), CFCs, HCFCs, HFCs - WJL-6000PRO 2021 Upgrade by Sabryna Wickings

Just because of the low price, I expected all sorts of difficulties to get this tool working properly. This was definitely not the case. I put in four AAA batteries, turned it on and found coolant. Here it is. no calibration, no tuning, nothing else. The device emits steady beeps. When it hits the coolant, the pace picks up. I haven't read the instructions yet as I don't need them, but it can be calibrated. The tip is not interchangeable.