I don’t know about the weight but last time I was on the Illumn site they had the Thrunite TH20 on sale for $25. It takes a 14500 I believe.
if you add the 45gm for an 18650, that H03 comes to 89 grams
the 18350 Armytek Tiara (48gm), plus an 18350 (21gm), totals 69 grams…
Highly recommended: Armytek modded to High CRI from Clemence
Here is a post about the quad E21A mod
and a pic of some of Clemences Quad E21A 2000k, being tested in a light of mine (not a Tiara)
not exactly “B”LF, eh?
I like my TH20, but from what I have read it is not very light compared to other headlights. Don’t have any specific data for comparison, I am sure Thrunite has the weight listed on their website.
Ran across this. Andrew and Amanda have the Nitecore EC11 on sale for $39.00 right now. Don’t know for how long.
I’m sure someone could easily make a flashlight as small as the lux-rc minion.
All it takes is a small cylinder with the LEDs on the driver PCB and a piece of glass.
No optics or anything, just a mule.
Using flat LEDs like XP-L HIs or black flats could reduce the height even further.
But for some reason nobody does it. 
If only they made a version of the S Mini sized for 18350. Le sigh.
A nice challenge for CRX !
Smallest 18350 light I’ve made was the copper & aluminium triple with FET driver & tail clicky.
Length – 60 mm
Width – 25 mm
Weight – 97 grams (with cell)
Max – 1400lm
10/11/2018
1/6/2019
update, I disagree with my former self
I tried an Eye10 and the detents are inconsistent and not spaced to my liking
it has given me a new appreciation for my RRT-01 smooth ramping dial… maybe I should try some hi cap IMR 18350… hmm
I think one of these protected button tops might be good… the flat top version does not work in the RRT-01
pic is a link to review
Can anyone confirm if these fit the RRT-01? (not too long?)
they are for sale here:
Probably too long. I made a custom flat top protected for my 01, very tight fit.
I had to grind the tail pin down and alter the RvPo ring to make it fit.
I could be wrong though, would be best if you could measure somehow with the cells you have and thin spacers?
darn
Protected Keepower, length: 39 mm
Protected Fenix 16340, length: 34 mm
maybe I need to go to the store and try the cell out in my RRT-01 before I buy it…
That would be good. Screw gently though, maybe with the o-ring off 
CR123A is taller than 16340 too.
A 16340 with USB charging PCB is the same length as a CR123A.
Often 16340 lights are also meant to take CR123A, or vice versa.
Sorry to bring up this old thread, but I’m curious about if anyone here carries a 18350 flashlight in the keychain and how does it work out for you.
I’m interested in the new amutorch E3S which is probably the shortest 18350 triple out there, but now I’m not sure if to get it or save some money and convert my FW3A into the shorty which will cost me $13 with shipping. Ideally it would be the D4V2 or KR4 because of the fancy aux leds but i don’t how how bulky/heavy would that be on a keychain.
I don’t want to get a 16340 light because I am already carrying a Jetbeam mkii modded with a FET driver. Beam is pretty amazing but the short runtime has failed me on several occasions.
Any input is appreciated.
The Jetbeam is pretty small. Not sure you want a short D4V2 on your keychain.
Also, if you like the Jet-II beam, would you want to replace it for a floody light?
Edit: I cannot prove it, but would consider that the Jetbeam may have a longer runtime than the D4V2/18350 at the same brightness.
I would research to find the weight, with battery inside, for each of the 5 lights you mention, and then choose the lowest carry weight, in a light with the features you want.
No matter what light you choose, carry a spare battery, so runtime will not be an issue.
here is an example of a 16340 battery storage case that is quite small and lightweight
You may want to check this: Flashlight Comparison Request Thread - #10 by DrDevil
BTW, in case you prefer longer runtimes, you can get a light that takes 14500 and get some Vapcell or Shockli cells that are above 1000mAh. (more than the 800mAh that the best 16340 has). :+1: