Beep & Light Alerts: When voltage is detected, the pen beeps and glows red. Higher voltage or closer range causes faster beeping. Red screen means high voltage/live wire; green means low volt /neutral. Non-Contact Detection: NCV sensor lets you detect AC voltage without touching wires. Simply place the tip near a cable or outlet to check for power and identify live/neutral wires. Breakpoint finder included. Dual Mode Switch: Detects 12–1000V or 48–1000V AC. When "S" appears on the screen, it’s high sensitivity mode (12–1000V); no "S" means low sensitive (48–1000V). Easily adjust based on testing needs. When detecting voltages above 48V, use low sensitivity mode if you can get close to the cable to reduce false alerts. Versatile Use: Ideal for home wiring, outlets,socket, breaker panels, lighting fixtures,lamp and power tools. Perfect for electricians, repair workers, and DIY enthusiasts. For environments with obstructions or when you cannot get close to the cable, use high sensitivity mode. Please note that high sensitivity mode may be affected by electromagnetic interference, so adjust based on the environment. Compact & Efficient: Bright LED flashlight for dark spaces. Alerts when battery drops below 2.3V, auto shut-off after 3 minutes. Uses 2 × AAA batteries (not included); lightweight and portable.