Is there anything else with similar dimensions (or less) in 20$ price range worth considering? If topic linked above is true (“world’s smallest”) then looking for slightly larger but cheaper.
The one you linked is the DQG mini 18650. It’s not very popular around here. I have a first run DQG 18650 and it’s awful. The battery tube tapers going towards the back. The light runs fine on my AW IMR 18650s. But if I try any other 18650s they go in, get stuck in the tapering and then never come out. I ended up drilling a hole in the bottom of the tube so I could insert something to push out my cells.
The second run DQG18650 allows the bottom of the tube to unscrew, so my problem shouldn’t be an issue. However, it reportedly has a problem of the screw threads going into the o-ring slot, so the light chews up o-rings when used.
Basically, it’s just not a very good light, even though it IS small.
The only other 18650 light that is of similar small size is the Zebralight SC62d. It’s far better built than the DQG18650 and has a much better UI. But on the other hand, the maximum output is lower and it costs $85.
The only other way to get such a small 18650 light is to mod one.
I have the Convoy S6 and highly recommend it, also just had a Small Sun ZY-T29 given to me and it’s pretty nice as well. The side clicky is a pretty neat feature. I’ve modified it with a Qlite driver and flashed my own preference of mode levels to make it more enjoyable.
The Convoy S6 ends up over $20 usually when adding the driver and emitter.
The Small Sun ZY-T29 I linked is ready for a battery, for $13.06 at Fast Tech.
All things being equal, I really think the S6 is a great choice. I carry one in a fannypack with camera equipment and it’s very slim, the profile makes it fit easily into a corner and the tail clicky makes it safer than a side clicky, not as easy to accidentally engage.