Freon leak detectors operate on R22, R134A, R404a, R410A and all halogenated refrigerants (including , , HCFCs and blends). Audible and visual gas leak indicator and dual battery indicator. Reacts to any halogenation. This includes, but is not limited to: After turning the switch, the detector is ready for use. Selectable sensitivity from 1 to 7 levels Response time: 3s Operating temperature: 0℃-52℃ (30℉ to 125℉) Highest sensitivity to all halogenated refrigerants: 0.21oz/year Battery life: about 50 hours of normal use Operating 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 x AAA alkaline batteries. (not included) Color: black Material: plastic Package Contents: 2 x 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 a little different from the real