I'll tell you about a really nice little-known light called the N-Light B10. It has some limitations, but it works very nicely.
I got this light in a very cheap deal from someone who thought it was defective. He put a CR123 in it, and in blinked all the time, and wouldn't run normally.
It turns out that it is for UNPROTECTED lithium-ion 16340 ONLY and it blinks when its low-battery protection circuit is about to kick in at 3v. It thought the CR123 was a nearly depleted 16340, and was signaling that it's going to need changing. The 3v CR123 just didn't have the voltage that this light is supposed to run on. It needs the 4.2v of the lithium-ion rechargeables. No protected 16340 batteries will fit, so it is very battery specific.
But this little light performs! It is only 2.5" long, is all stainless steel, has a neutral XPG in it, and puts out 280 lumens on high. It's a 3-mode twisty.
They call it the "Atomic Bomb" because it has a bomb-like shape, and is actually a 16340 copy of the famous Jil-Lite from Korea. The Jil-Lite was CR2.
Real nice tint. Great beam shape, nice and clean. Super compact and easy to carry. Reliable, and no mode-skipping.
I really like it.
The problem is that unprotected 16340 batteries are getting hard to find now. And protected ones won't fit.
This little N-Light B10 has found its place as my go to light around the house when I just want to grab something that will do just about anything, and I don't have to be concerned about it getting scratched or dropped, or anything. I got it for less than $10 shipped, even though it originally sold for something like $40.
It's no longer available, apparently. CNQualityGoods used to have it, but not any more.
Best Chinese light I ever had.
Of course, if anything ever goes wrong with it, or unprotected 16340 cells are no longer made, then that's the end of it.