I have several of these, and I love them. Lots of light, good battery life, and a simple on/off switch (not multi-level brightness). The only downside is that the spot is relatively small, and isn't adjustable.
The COAST G20 is a really good penlight, the information for it doesn’t say how many lumens it is but i'm pretty sure it's about 50. The flashlight isn’t bright enough for something like hiking at night but it's great for indoors or outside projects. The flashlight is very small and thin so it's easy to carry wherever you go. The O-ring on the lens of mine fell out but mine appeared to be waterproof(even though it isn’t advertised as so). The pocket clip of mine breaks but you can order replacements so it's easy to fix. Overall the G20 is a great light and I would definitely recommend it.
Mine went through an entire cycle in the washer after I accidentally left it in my pocket. I expected it would be ruined, but it still works just fine. Super quality product!
I bought two of these little beauties in colors matching the cars they'll be used in. I believe in being prepared with a flashlight at all times, and there are jobs that are no good for a camera light. The focused light on this flashlight is perfect for most peek-under-the-hood jobs. Couldn't be happier with this little light.