This Scosche car stereo tool kit provides you with everything you need to quickly install your car stereo like a professional. It has a voltage test light with a built-in flashlight that powers from any 12V power outlet and lets you test or troubleshoot your power and ground wires. The angled panel tool is for safely removing your vehicle’s door or dash panel without marring or scratching the surface. As for the RCA cable tool, it is used to pull or route your amps RCA cables through hard to reach areas.