product features: 1. Sharp steel probes can easily pierce wire insulation to check circuits. 2. The probe pen is ideal for checking circuits, fuses, switches and wiring in cars, trailers, boats, motorcycles and other low voltage systems. 3. Ground the alligator clip and test the circuit with a probe. When the light is on, there is electricity. product instructions: 1. Clip the measured alligator clip to the ground wire (such as the metal or negative pole of the car) 2. Measure the conductive metal in the test circuit with the needle of the electric pen 3. If the light bulb of the stylus will light up, it means that the measured point has formed a circuit and works normally. On the contrary, there is a fault at the measured point, which is to be checked. Product Specifications: Material: ABS+metal Color as shown Clamping capacity: 20A Bulb: 3 watt bulb (replaceable) Voltage test range: 6v-24v; Pen Length: 17.3 cm/6.8 inches Probe Length: 8.3 cm/3.3 inches Cord length: 96 cm / 37.8 inches Packing weight: 140g caution: 1. Due to the chip update, the working range is 6V to 24V, but the mark on the test pen body shows 6 to 12V, please do not order if you mind; 2. We default you have accepted when ordering. Thank you for your understanding,; 3. Since the world voltage is different, please allow a tolerance of 1.5V. Product List: 1*Test pen