Feature: 1. Automobile circuit maintenance: Wire piercing probe is a practical automobile circuit maintenance, detecting automobile wiring, providing the precise pressure required to puncture the insulation of wires. The needles are very fine, so that the wire is not broken. 2. Double headed: The product has two heads, yellow head is used to piercing, easy to locate. Red and black head provides quick circuit identification. 3. Sliding adjustment: The Wire piercing probe supports sliding adjustment, suitable for a variety of different wires, makes some of the more difficult testing connections easier and accurate testing. 4. Reliable material: Wire piercing probe is made of plastic material, featuring high toughness, wear-resistant, not easy to break, sturdy and durable. And it is high temperature resistant, insulating, reliable to use. 5. 2 sizes to choose: The product has 2 sizes, one rear socket is about 2mm/0.08inch, the other one is about 4mm/0.16inch. You can choose according to your needs. Specifications: Color: Black, red Material: Plastic Size: 2mm/4mm(as flows): 2mm: About 96 x 19.3 x 21.3 x 5.3 x 2mm/3.78 x 0.76 x 0.84 x 0.21 x 0.08inch(length x width x adjustable part length x piercing hook length x rear socket) 4mm: About 96 x 19.3 x 21.3 x 5.3 x 4mm/3.78 x 0.76 x 0.84 x 0.21 x 0.16inch(length x width x adjustable part length x piercing hook length x rear socket) Package Includes: 2pcs x Wire piercing probe Note: 1. Due to the light and screen difference, the items color may be slightly different from the pictures. 2. Please allow 0.5-2 cm differences due to manual measurement. How to use: 1. Remove the carbon needle, and use a spring clip to clamp the wire to be measured. 2. Hook the wire with the test hook, and then press the hook as soon as it is released, then start to twist the needle, and then plug the multimeter stick on it. 3. After plugging the multimeter stick, and then measuring, the voltage will come out. 4. After use, unplug it, unscrew the carbon needle, and take out the wire.