When I wanted something smaller than the ZL 600W, I considered both the D25LC2 and the D25C2 neutrals.
The D25C2 is thinner, but I got the D25LC2 neutral because I like single 18650 models and the form fit my hand.
For an excellent, high CRI, single-cell light, consider the LensLight Mini.
It's not an 18650. But runtime is listed as 1.5 hours on high -- not bad for a single 123a!
And the Mini is rated at 330 lumens on high (I got the single mode version.) The tint is warmer than the Eagletac neutrals and the beam is exceptionally clean -- a large round circle without apparent rings.
That's for close up. For far away, twist the light and you'll get a smaller, more concentrated beam that the company says is good for 200 yards. I'd say it works very well in the 50-100 yard range.
The McClicky switch is the best I've used. The Mini is 3.85 inches long -- perfect for me, not too short or too long -- and 1.06 inches in diameter. That's thicker than the Eagletac but thinner than the 600 W.
The downside is the price: $159.
A Ti version is twice the price.
These are USA-made, with an unusual Delrin clip that you'll either hate or grow to love.
I ordered one thinking I would see what the fuss was all about and likely send it back.
I still have it and it's become my favorite dog-walking light. And that's saying a lot for someone with two of the best lights on the planet, the ZL 600W and D25LC2.
If none of those three appeal to you (four, if you consider another favorite, the ZL 60W, another 18650 light), consider the Eagletac D25A, available in neutral.
Lights don't come much smaller. These things make the Nitecore D10 series look huge. Both use a single AA-size light. I like the D25A with a lithium ion rechargeable. That produces a near-blinding amount of light.
Unfortunately, it gets hot quickly and won't last long. I keep it that way and use it for my emergency EDC. If I wanted to be able to use the various modes, I'd opt for an AA alkaline with much less output.
I hope this helps. Good luck -- and have fun deciding.
