UL Certified CAT IV 600V AC, 24 to 600 V AC An LED flashlight in the tip operates independently of the tester functions and can be used to illuminate the work area press the flashlight button to turn it on/off the tester is set to flashlight off, flashlight will auto power off after 5 minutes Audible notification disable the tester can be operated with a visual only indication of voltage when working in noise sensitive/noise restricted area with the simple press of a speaker button Auto power off after 10 minutes of inactivity (no button pressed and no signals detected), the tester will emit one long beep (~0.5s) and then shut off note: if the flashlight is on, it will be also shut off Low battery indication if battery voltage is less than around 2.4V, the green led in the tip will flash 3 times and the buzzer will send out one long beep, then turn off the device, Manufacturer: IDEAL