Actually i didn't think i would personally use this as much as i have. First time seeing the tool, i couldn't figure out why it only has one ground tab on it. THEN after about 2 minutes later the light bulb went off (not literary) and i realized why. I thought it was broken to begin with but then i thought about it. The tool is actually a very good idea because as an example your diagnosing a window motor and you want to supply a ground. I completely understand you could just use a power probe but sometimes that's always not the best solution. This can hook to your test light and now you have that power and ground.Many probably don't know even on modern vehicles today, it's becoming hard to even find a ground on a car. If you do it's a poor connection or a painted surface. This actually is a 3 in 1. This can 1. Supply a power 2. Supply a ground 3. Check for an operational 12V socket because the center light does light up when you have a good power and ground.If it doesn't light up then you know something isn't working.The tool is plastic for anyone wondering, sometimes because there is only one side the has the tang (for the ground) it makes the tool off centered and wobble because the other side it open. If there was plastic and it was straight then i wouldn't be an issue. There are times were you need to find the "Spot". I would comment something but most likely inappropriate for Amazon. It is a very unquie tool to have inside because there are many times where you need to test for a power or ground and will not reach to the tool.I have used the tool multiple times and have been overall happy with it. No real issues other than sparked a once or twice due to my own personal fault but would definitely recommend to consider this as it a very helpful tool.