This handy little tool is for anyone who needs to test electrical circuits in cars, motorcycles, or other wiring without cutting or stripping the insulation. The set includes 4 piercing clips (two red, two black) and 2 multimeter lead connectors. You attach a clip to your multimeter lead, then clamp the clip onto a wire. By turning the end, a small needle inside pierces the wire's insulation to make contact with the conductor inside, allowing you to check voltage or continuity. The bright yellow bodies are easy to see, and the 'in-line retention' feature lets you detach the leads from the clips. The design is cost-effective because you can remove and sharpen the piercing tips if they get dull, instead of replacing the whole clip. A real time-saver for automotive electricians, DIY mechanics, or hobbyists troubleshooting electrical gremlins.