Adjustment of sensitivity: The unit features 5 levels of sensitivity adjustment. Slower and closer movement of the probe greatly improves the likelihood of finding a leak. When gas leakage is discovered, a "di di" sound will be heard. The greater the refrigerant leak, the more rapid the sound, and the indicator light will flash quickly. Upgraded: At each area checked, the probe should be moved around the location at a rate no more than 25 to 50 mm/second (1-2 in/second), and no more than 5 mm (1/4 in) from the surface, completely around the position. When leaked gas is detected, the audible tone will change to a "siren" type sound. The greater the refrigerant concentration, the louder and more rapid the siren. At the same time, the digital display screen shows the corresponding sensitivity level quickly. Easy setup: The leak detector features an automatic circuit and a reset function that sets itself to ignore the ambient level of halogen gas. Upon initial switch-on, wait 6 seconds to enter the optimal detection state. Widely used: It can detect all kinds of halogen refrigerants including HFOs, CFCs, HCFCs, HFCs, and mixed refrigerants such as HVAC, R22, R410A, R134A, R1234yf. It can be used for almost all air-conditioning and refrigeration systems, including automotive, household, and commercial refrigeration equipment. Working temperature: 0°C to 52°C (32°F to 125°F). Maximum sensitivity is 0.14 oz/yr (for halogen refrigerants). Power source: 6V DC, requires 4 x AAA batteries (not included). Color: Red & Black Material: ABS Dimensions: 22.9 cm x 6.5 cm x 6.5 cm (9.01 x 2.56 x 2.56 inches) Fixed probe length: 20 cm (7.87 inches) Package Contents: 1 x Air Conditioning Refrigerant Leak Detector (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 to appear slightly different from the actual item. Measurement allowance is +/- 1-3 cm.