Automatic self-test on each startup, including vibration function and LED check (. 1 second), ensuring safety, with continuous background checks every 5 seconds. CAT IV 1000 certification for high-voltage environments. Non-contact voltage detection: Fast and safe operation without direct contact. design: TPE housing with IP67 dust/water resistance, tested for 2-meter drop resistance. Functions: Built-in flashlight: Operates in low-light conditions via a dedicated button. Auto-off after ~5 minutes of inactivity. Dual voltage ranges: High sensitivity mode: 24V 1000V (50 60Hz) Standard mode: 90V 1000V (50 60Hz) Multi-alert system: Green LED: Ready/No voltage detected. Orange LED: Low voltage detected. Red LED: AC voltage detected. Audible beep + vibration when voltage is detected. Low battery warning: Audio alert + dual LED flashing before automatic shutdown. Specifications: Model: 1000-17 Safety rating: CAT IV 1000 V Protection class: IP67 AC voltage range: 24V 1000V (50 60Hz) / 90V 1000V (50 60Hz) Operating temperature: -10°C to 50°C Battery: 2x 1.5V LR03 (AAA) (Not included) Dimensions: 161.5 x 28 x 33 mm Color: As shown Material: ABS Package Contents: 1*test pencil Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.