I reccomend this especially because it does NOT have an LED. Basically, it is a flashlight without a switch. And like a flashlight with a filament buld, I had to take it apart and realign the contacts so it would be more reliable. With a filament bulb I was able to detect a half-broken wire because the buld was dim instead of bright, something you can't get from an LED! AND, do get an extra bulb, the ones with the screw in threads for the springy thingy. I forgot to disconnect the battery on the '65 Olds and it ate my buld, so to speak. Make sure you also have a small enough phillips screwdriver to access the buld. To test this device, simply touch the clip to the tip. If it don't want to glow, give it a tap, just like an old flashlight. I gave this a slightly low rating because I had to disassemble and reassemble it, It was simple. So...it is not what the tool does, it is about what one can do with the tool.