L21A SBT90.2 should not reach such a range.
I need to make new molds to produce the corresponding diffuser and holster
I ordered the piece parts today to build my own L21A with the KW CULPM1.TG from your Aliexpress store 
Before seeing this post.
Also did the same a few weeks ago to build a C8+ with the KW CSLNM1.TG now see your selling a prebuilt 
My timing is impeccable lol
Waiting for it to go live 
How much? A shrimp's hair? :-D LoL!
I have some fine grit wet/dry sandpaper lying around. 
Same here :person_facepalming:
Actually yes.
I have sanded down several, some ended up too thin, but the standard thickness was too thick.
Ordered the CULPM and 4040 gaskets to see whether it will perform better.
Will try to get 8+ A by using a sense resistance mod.
Just use a fet like a video on youtube using the BLF A6 driver. I’ll be running a few tests when I get mine
So guys, I’ve been looking for a pocket thrower (one without a huge reflector head). This new (grey) convoy S21B with osram led should do the trick right? I don’t need a LEP or anything close to it. Just a portable, regular looking light that can put out a long, throwy beam. Kinda like a pocket white laser without breaking the bank.
For 24$ i wouldn't be thinking at all but buy it.
Which i did...:)
What range are you thinking though?
An effort ages ago, and a half-arsed effort recently:
https://www.reddit.com/r/flashlight/comments/cp8ou2/we_need_a_convoy_comparison_spreadsheet/ewnx5nf/
and
Thx oweban for this list.
Should be sticky if you ask me...
I need to spend a lot more time on both lists, and I don’t have a lot of readings for most of them. As people have mentioned, there’s an awful lot of candela and lumen readings missing from items - so unless there’s a hefty shipment of lights coming my way, they’ll have to stay blank 
Does Convoy not check the waterproof rating on their models? It’s always missing and kind of need it for selling
While doable, it's far from being the best option. The regulated drivers we are discussing here use a regulated MOSFET or array of MOSFET switches, done by sensing voltage drop on a small sense resistor. The only additional resistance versus a pure MOSFET driver is that of the sense resistor stack, i.e. super small. However, if you remove the sense resistor (plus regulation stage and logic) the penalty is having to resort to pulse width modulation for all modes but the highest, plus being unregulated which means it can go above the optimum max driving current (undesirable and unoptimal) unless the flashlight operator is knowledgeable and takes good care.
I got into this hobby about a month ago and told myself I’d pace my purchases. Well, I’ve added 8 new lights plus 4 on the way (2 from convoy, including a black S21B before I found out it’s available in grey). So much for pacing.
Anyway, still looking for a pocket thrower under $40. This one fits the bill but I’m trying to wait for the S21B to arrive to see if I really do like the body. I might just bite and get this one too.
Also looking at copper edc18 but it’s hard bc I have a regular edc18 coming next Monday.
I guess what I’m trying to say is: I need to stop “not think and buy”.
Price: $40 max. I can stretch a bit if needed.
Throw distance: 500meters roughly
I had my eye on a K1 but it’s too big and a bit out of my price range. I’m interested in many aspects of this hobby (edc, output, material, aux led, tint, CRI, etc) so I need to keep some budget available for other lights.
BTW, noob question: how are people swapping emitters? I see individual emitters sold and people making 3-led s2+ but how are you installing emitters onto the pcb? Soldering? I don’t see any lead where emitters attached to pcb.
At peak emitter output, that setup should be good for ~40kcd (NM1 @ ~4.5A). That’d be about 400m ANSI. I generally cut that number in half for real world use.
edit:
For more range (reaching 500+m ANSI) and remaining pocketable, I would recommend the Convoy M2. This is 18650, and with the NM1 and 4.3A I’m getting 80kcd. If you want 21700, then there is the M21B, a bit too big for the pocket IMO, but that’ll do closer to 100kcd with the 1mm Osram. Take about 20% off cd values to go up to the 2mm/PM1.
That leaves the M2 with a boost HX and 8A driver my recommendation for best budget (truly) pocketable thrower.
That said, S21B won’t be a slouch. Just won’t do you any good at 500m.
I put together a c8+ with the 20w green osram and the convoy 5 amp single mode driver last night. It worked perfectly for a few hours and then I turned if on and it was blinking/flashing like crazy. All my connections were fine but I found a little loose ball of solder stuck on the driver near where convoy soldered their pos and neg wires. Did it get shorted out maybe? I swapped in a 1amp driver and the led worked fine.
Disregard. I’m an idiot and somehow switched the mode grouping… totally forgot it was the 12 mode biscotti driver lol