Features: Voltage measurement with bulb load: By measuring the brightness of the bulb of the electric pen, combined with the voltmeter function of the electric pen, more accurate voltage measurement can be realized and the fault diagnosis ability can be improved Voltage polarity display function: quickly distinguish the positive and negative poles of the power supply through the LED light prompt.Positive and negative voltages can be measured: for the load plug, you can use the probe directly connected to the clip combined with the probe of the test pen to directly perform load simulation measurement, which is convenient for fault diagnosis Choose 12V5W: the working voltage range of the device is 5V-30V, if it exceeds 30V, it may burn out the electric pen.Voltage measurement function: voltage measurement function, the of use is the same as the multimeter voltage measurement 3 modes can be switched at will: There are 3 modes in total. The mode switch is operated by the physical button on the main body of the electronic pen. Press and release the button to cycle through the three working modes. Widely used in the auto repair industry: especially suitable for car repair technicians and family business vehicle maintenance and repair, etc. Product name: Automobile circuit testing pen Product model: P50 Voltage range: 5V-30V Material: plastic colour: As shown Package Contents: 1 x Circuit test pen 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.