Two-color LED light The freon tester comes with a UV lamp + a white flashlight. UV lamp is used with fluorescent agent, white light is suitable for illuminating dark and small places. (LED light contains battery) Halogen Leak Detector Upgraded Version of WJL-6000 WJL-6000Pro Halogen Leak Detector is the upgraded version of classic WJL-6000 with higher sensitivity. The new improved LCD screen displays the sensitivity level and refrigerant gas leak level, even multiple alarm functions. Refrigeration Leak Detector with Superior Sensitivity20cm flexible detection tip with a higher sensitivity (up to 3g/year) compared to WJL-6000 (7g/year), it can work continuously for 50 hours with 4 AAA batteries. Batteries are not included in the package Refrigerant Detector with Leak Level VisualizationThe new improved LCD screen will display the refrigerant gas leak level. Additionally, adjust the sensitivity by pressing the button, the LCD screen will display the sensitivity level. Freon Tester with Multi-Alarms The leak tester display audible and visual alarms can easily help you locate the leak. Once a gas leak is detected, the frequency of beeps will increase. The bigger the gas leak, the faster the buzzer beeps, at the same time, the LCD screen displays the leak level. Air conditioning leak detector detects all halogen gas It can detect all types of halogen refrigerants including CFC, HFC, HCFC, HC, HFO and mixed refrigerants such as R11/R22/R404a/R410a/R600a/R1234yf and blends such as AZ-50, HP62, MP39 etc. and response within 3 seconds.