Freon leak detectors trigger on R22, R134A, R404a, R410A and all halogenated refrigerants (including HFC, CFC, HCFC and mixtures). Audible and visual gas leak indicator and dual battery indicator. Will react to all halogenation. This includes but is not limited to: After rotating the switch, the detector is ready for use. 1-7 level selectable sensitivity Response time: 3s Working temperature: 0℃-52℃ (30℉ to 125℉) The highest sensitivity to all halogenated refrigerants: 0.21oz/yr Battery life: about 50 hours of normal use Operation mode: continuous and unlimited Fixed probe length: 7.87 (in) Dimensions: 1.37 x 1.37 x 5.90 inches Warm-up time: about 6 seconds Reset time: two to ten seconds Power supply: 6V DC, 4 AAA alkaline batteries. (not include) The Freon tester comes with UV lamp + white flashlight. UV lamp is used with fluorescent agent, white light is suitable for illuminating dark and small places.(LED light contains battery) Colour: Black+Yellow Material: ABS Package Contents: 1 x Halogen 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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.