Recommend a host please for pocket UV 20mm head.

Right, today my ‘Seoul viosys’ uv led arrived and i have decided to make a pocket UV torch from it and i wondered if someone would recommend a host, its a 20mm mcpcb but has 3 leds and a reflector. Ideally, i’d like a side switch system like the sofirn sc31b :
Ideally runs off 1 18650.

https://www.aliexpress.com/item/32917707163.html?spm=a2g0o.detail.1000014.15.54651e30cmpusY&gps-id=pcDetailBottomMoreOtherSeller&scm=1007.13338.128125.0&scm_id=1007.13338.128125.0&scm-url=1007.13338.128125.0&pvid=21fac4e1-8096-4314-8883-3b74bf813882

LED:
https://1drv.ms/u/s!AoEv-9vBdzh_hfoppko5e48R1-aLOw
https://1drv.ms/u/s!AoEv-9vBdzh_hfoqLWc_HpnAeQNPEg

It’s trying to find a host with a 20mm head and shallow enough so the optics don’t rattle around.

The stock Convoy S2+ has a 20mm glass lens plus a circa 20mm deep reflector.

It has a screw-in pill that comes with a 16.5mm recess for a led-board at the front side.
Advantage of the S2+ is that you must screw in the pill until the reflector “hits” the glass lens.
So you can squeeze out any empty room in the head section. No rattle.

Your led-board seems to be over 16mm wide, maybe about at big as the optics?
In that case you have to find a way to get rid of the rim around the recess until you get one flat surface.
Possible snag: never tried such short optics, and the standard reflector is about 20mm long.
Maybe the thread inside the head does not reach far enough to make the shallow optics “hit” the glass lens.
In that case you must find something that goes in between the top of the pill and the bottom of the led board.
Preferably made out of copper, to lead the heat away from the lead board.

And eh, I would replace the clear glass lens by a ZWB2 filter.

Brilliant info, thank you. Gives me enough of a lead to narrow down my searches. Yep, all my UV have the filters. I dropped lucky with a chap on ebay selling them for peanuts so i ordered all the sizes i needed. Sadly, his account was ‘closed’ by ebay but the filters arrived and work superbly.