The Astrolux S42 has some significant problems. I own one and wouldn't recommend it.
Astrolux is taking steps to fix some of the problems, but even with the fix, I doubt I'd recommend it.
What I like about the S42
* price
* light weight
* quad emitters
What I don't like about the S42
* initial batch's battery tubes are too short. Won't fit 18350 or 16340. Astrolux is making a new batch of longer battery tubes and will ship them out for free to owners of the original batch upon request.
* Rubber USB cover falls out of position far too easily. Astrolux is making a redesigned cover that supposedly will stay in place better and will send them out for free to owners of the original batch upon request. However, I am concerned that the socket for the USB cover may not be deep enough and even a redesigned cover might not stay in place. No way to be sure without seeing the new cover.
* Awful UI - This is the biggest sticking point in my opinion. The UI is absolutely horrible.
mode group 1 (7 modes)
Long click for on to moonlight (no memory).
from the on position short click to advance modes
from moonlight long click to jump to turbo. (turbo output decays smoothly but steeply over 30 seconds or so)
double-click: swap to mode group 2
mode group 2 (4 modes):
this mode group has memory.
long click to turn on in last used mode.
short click to cycle to next mode
double-click: swap to mode group 1
cannot access moonlight or turbo in this mode.
My problems with this UI:
- very unintuitive
- no shortcut to turbo from off
- no mode memory except in mode group 2, but that group lacks moonlight and turbo.
- long click for off and on
I recommend steering clear of the S42. There are other, much better choices out there, such as the Zanflare F1.