Low battery indication - if battery voltage is less than around 2.4 V, the green led in the tip will flash 3 times and the buzzer will send out one long beep, then turn off the device|Senses 2 Vage ranges 12-1000 VAC or 50-1000 VAC allowing detection of low voltage (doorbells, thermostats, etc.) and standard voltage in tamper-resistant outlets when the tip is located near the Hot receptacle and/or Hot Connection point on the outlet|Dust Tight and Water proof (1 m for 30 min) Industrial Design makes this tester easy to grip and capable of sustaining a drop from 6.5 ft (2 m)|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|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 min 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