I've found the Astrolux S41S (with an extender for the 18650 battery and a tritium vial on lanyard) to be a great travel light (with a few exceptions). Let me explain:

* It starts in moonlight mode (I think about 0.5-1 lumen). Great for not blinding myself in the middle of the night in a hotel room I can't find my way around.
* It has a great flood beam for searching for things dropped under beds, airplane seats, etc.
* The various modes always seem to let me find a good level of output for what I need
* It has enough power to check out what's going on in the yard
* It has a very sturdy feel
* It takes an 18650 (and I carry a USB-rechargeable 18650 in it, so I can always charge it)
* It can stand on the tail cap (although not well)
* It can also take a single 18350 (or even a CR123A in a pinch)
* It has a good grip (tough knurling, maybe a tad too aggressive)
* It goes in the pocket fairly well (could be better--again, that knurling is somewhat aggressive). It doesn't have any sharp areas that would poke (like a defense bezel). I want a smooth light with enough grip that I won't drop it easily.

It has a few cons which I'm hoping to be able to correct with my next light:

* It is heavy (made from stainless steel). I like the sturdyness, but I'd prefer titanium for weight.
* I'm worried that the 1600 lumen mode creates too much heat. I forget where, but I read a post about someone burning one out. I want my light to not let me break it as long as I'm using it with the modes it provides.
* It can roll off the counter (perfectly round). I'd prefer a bezel or clip or something that would prevent this. My old surefire 6P LED Defender did a good job of this with the hex bezel, but I just need a slight notch or something.
* It has no tritium inserts so I need to put the tritium on a lanyard
* It's wider than it needs to be (thick stainless)
* The tailcap looks weird in semi-clear rubber
* There are a few too many modes and special clicks needed

I've filled out the questionnaire below.

1) How would you prefer to purchase the light?

This will be mail-order or Online (location doesn't matter).

2) Budget: An easy question, but you may change your mind after answering the rest! :-)

Up to $300. (hopefully? I know titanium can add a lot)

3) Format:

I want a flashlight (hand held/self contained).

4) Size:

Single 18650 (if it could adjust to fit other lithium cells (e.g., with a smaller extender tube), that would be cool)

5) Emitter/Light source:

LED - bonus would be a warmer beam and/or higher CRI numbers

6) Manufacturer:

Any of the following:

I want to buy a light from a large/traditional manufacturer that is ready to go out of the box.
I would like a light from a specialty manufacturer (Possibly limited run/Custom).
I am interested in assembling my own components. (for example a “host” or flashlight body from one manufacturer, and a “drop-in” emitter from another source).

7) What power source do you want to use?

18650. I'd prefer if it could also take two CR123As

7a) If you have selected a rechargeable option

Must have: option to swap battery
Would prefer: option to charge via USB (preferably USB-C, but I'll take USB micro) (would not give up waterproofness for this)

8) How much genuine out the front (OTF) light do you want/need? Sometimes you can have too much light (trying to read up close up with a 100 lumen light is not a happy experience).

This is going to be a "travel" light

I like the moonlight (~1 lumen?) default mode of the Astrolux S41S.
I'd like several modes going up to 1000 lumens.

9) Flood vs Throw: Flood covers an area, Throw reaches out to a distance.

Again, I like the Astrolux S41S here: pretty wide, but at 1000 lumens, you can light up a yard. No "hot center", but it could be a tad narrower than the S41S.

9a) Distance: How far away will you typically need to see with this light (check all that apply)

Both of these:
Less than 5 yards/meters (looking for something inside a dark shed/garage/basement)
5-20 yards/meters (check out a noise in the backyard)

10) Runtime: Not over-inflated manufacturer runtime claims, but usable brightness measured from first activation to 50% with new batteries (Measured on maximum continuous output).

As long as the light is competitively efficient, I'll be happy with whatever my 18650 can deliver.

11) Durability/Usage: Generally the old phrase “you get what you pay for” is very accurate for flashlights.

Very Important (Camping, Backpacking, Car Glove-box).
I've heard concerns about the Astrolux S41S at the max output. I would want to be confident that I could run this thing at max output and it wouldn't overheat and break. If that means cutting down the output after a few minutes of run time, that's a sacrifice I'm willing to make. Just don't surprise me by breaking.

I want to have this light for a long time - maybe even pass it on some day.

12) Switch Size, Type, and location (choose all that apply):

I want a tail mounted switch (found on the majority of today’s high end lights).

13) User Interface (UI) and mode selection. Select all that apply.

Probably (what I'm most used to): I want multiple light levels. (Some lights have 5-16 light levels.)
I'd also consider: "I want a programmable light."

Less important, but potentially desirable:
I want a strobe mode. (Oscillating pattern to confuse/blind aka "Police Mode")
I want SOS mode. (blinks in ...---... emergency pattern)
I want a beacon mode. (Regular flashes at full power to show location.)


Titanium (durable and nearly as lightweight as aluminum, but can be moderately to significantly more expensive).

15) Water resistance

I'd prefer IPX8 (Submersible to greater than 1 meter for 4 hours)

16) Storage conditions
I would like flexibility here, but practically speaking, it will probably be in the house 95% of the time. The other case would be in an automobile potentially.

17) Special Needs/extras: Is there anything else you want or need that hasn't been mentioned? Select any/all below.

* As compact as an 18650 can be (no extra length or width used up without reason)
* Tritium placed so it would be hard to not be able to see at least one tritium
* Replaceable tritium (worried about gluing tritium in and not being able to replace after they half life away)
* First click is moonlight mode
* Not perfectly round (so it won't roll off a counter)
* Stable on its tail cap pointed at the ceiling (like a lanturn) the Astrolux S41S tail cap design makes it somewhat unstable when pointed at the ceiling

* Charge indicator (or low bat warning giving maybe 30% left?)
* Low red light would be great, but not needed
* Magnetic charge port would be cool