NEW FEATURE - We have upgraded the voltage tester based on customer feedback. A sensitivity adjustment knob has been added to test voltage more accurately. With this button, you can select the AC voltage range of 12V-1000V or 48V-1000V, which is more flexible for you to use the electrical voltage tester. 3 VOLTAGE LEVEL INDICATOR LIGHT - NCV sensitivity automatically adjusts from low, medium and high while indicating the voltage level with a beep sound. You can know the voltage directly from the indicator light which shows the voltage level. Accurately detects AC voltage ranging from 12V to 1000V or 48V to 1000V. AUTO POWER OFF - requires 2 x 1.5V AAA batteries (not included), power off automatic after no operation for 3 minutes to save power. Lightweight and durable construction with handy pocket clip, a perfect handy tool for electricians or everyday use. LOW VOLTAGE INDICATOR AND LED LIGHT - The bright prompt of low voltage LED and LED light. alarm can warn you to replace the battery in time, while the LED light allows operation even in a dark environment. NO CONTACT SOUND ALARM ELECTRICAL VOLTAGE TESTER - Bring the probe closer to the wire . When the signal is strong, a red light appears and flashes at H level. When the signal is weak, it displays a yellow light and flashes at L level