value of firewire according to the voltage. Zeroline & Fireline Detection: When the fireline is detected, the backlight turns red an alarm sound is issued, and the zeroline being tested has no response. Breakpoint Judgment: Automatic breakpoint detection function, using the NCV function to sense the voltage, along the energized wire to find a normal place to alarm, breakpoint sensing becomes weak or no response. Buzzer Alarm: By sensing the strength of the signal, the buzzer sends out different frequency alarms. The red backlight flashes at high signal intensity, and the green backlight flashes at medium to low signal strength. LED Light Function: With LED light to help you illuminate and use when measuring in a dark environment. Multi-purpose Design: It is widely used in homes, offices, power distribution rooms, industrial equipment, circuit maintenance, electronic and digital equipment, etc. Specifications: Name: Electrical Test Pen Material: plastics Type: with silicone cover, without silicone cover (optional) Battery : 2 * 1.5V AAA battery (not included) Alternating current voltage: 12-300V Resolution: 1V Accuracy: 5.0% Dispaly: LCD display Sampling rate: 0.5 second Alarm mode: analogue bar, backlight and beep Automatic shut-off time: about 5 minutes Operating temperature and humidity: 0~40, 0~90%RH Storage temperature and humidity: -20~60, 0~75%RH Working altitude: 2000m max Item size: 22 * 22.5 * 188mm / 0.87 * 0.89 * 7.40in Item weight: 51g / 1.80ounce Package size: 198 * 45 * 26mm / 7.80 * 1.77 * 1.02in Package weight: 92g / 3.25ounce Packing List (without silicone cover): 1 * Electrical Test Pen OR Packing List (with silicone cover): 1 * Electrical Test Pen 1 * Silicone Cover