Follow up here;
Sorry, I meant the PT30:
PT30... thanks. The $100 price drew my attention. This would have been a steal if Tank hadnt blatantly lied about the nichia emiter. Also thanks for the CPF link. As stated, "The NCSU033B has a single emitter and a four emitter version is available as NC4U133. Nichia doesn't make these UV LEDs in a three emitter version." Thats all I needed to know. It seems that the 365nm version 501 at Kai is still fairly good for the price and for what you get. I had intended this for aircraft engine inspections when looking for oil leaks. The flood beam of a true quad nichia for $100 just sounded to good to be true.
I've seen many fluorescent lamps (4w or 9w) for very low prices.
Maybe they can help?
I have no idea how strong is their beam, but it's probably much more floody than the LEDs.
Oh, and Tank007 also have a 3W TK-566 version, but I wouldn't count on it to be stronger than the Kai's offering.
It's also expensive, and from what I see it only has two emitters not three (so I wonder how they can call it 3W...). But it would be interesting to compare the KD drop-in with the 556.
?
I never saw a photo of the LED - do you have a link?
Interesting.
I wonder if they also managed to squeeze four emitters into another version... :)
It's quite mysterious how no one knows what this LED is, while it is so ubiquitous.
If only the pictures in alibaba/taobao were of better quality... 
Nichia NC4U134 through NC4U134
Product sheet: http://www.nichia.co.jp/en/product/uvled.html
Data sheet: http://www.nichia.co.jp/specification/en/product/led/NC4U133-E.pdf
It looks like the group buy attempt going around the forums never came to fruition.
Considering Nichia is reportedly getting $223 for the quad LED and a custom high voltage driver would be needed to complete the build, this might be a good alternative.
Who's going to be the first to buy and review one? 
That's for CPF rich guys...
Depends what you want, but 395-400nm isn't as good as 365nm for most purposes. I was interested in the KD drop-in but I got the Tank007 PT30 instead.
I run mine off a 18650. here are some pics I took. it's really had to get accurate representatives since the camera picks up UV. I find that some bills will also show up but not all. The wavelength is too close to visable IMO. I'd like a 365nm emitter, but the good news it the output is pretty good as is. I'd hate to have it driven less. Sorry about the links, I've never been on a site that used HTML for pics [IM59-1.jpg[/IMG]
Details
Ultrafire 501B UV 365nm Flashlight(1*18650/2*16340)
Brand:Ultrafire
Mode:501B Wave
length:365nm
Battery type:1*18650/2*16340
Emitter: UV 3-Lumen
Price Intelligence on Aberdeen, Bangor, Bradford, Brighton, Bristol, Cambridge, Canterbury, Cardiff, Carlisle, Chester, Chichester, Coventry, Derby, Dundee, Durham, Edinburgh, Ely, Exeter,Glasgow, Gloucester, Hereford, Hull, Inverness, Lancaster, Leeds, Leicester, Lichfield, Lincoln, Liverpool, London, Manchester, Newcastle, Newport, Norwich, Nottingham, Oxford,Peterborough, Plymouth, Portsmouth, Preston, Ripon, Salford, Salisbury, Sheffield, Southampton, St Albans, Stirling, Stoke, Sunderland, Swansea, Truro, Wakefield, Wells, Westminster,Winchester, Wolverhampton, Worcester, York,
Really tempted to snag a few of these from KD to salvage the emitter.
Does anyone know the wavelength of the two UV dropins from Manafont?
I ordered the 365nm 501B from Kaidomain. Now I wonder... is it useful to run it on two CR123A's? KD suggests it should work but I don't know about the driver.
I don't really feel like getting into Li-ion cells for just this one little-used light. Or is this light only useful if modded?
So I got the KAIdomain 501b light, but didn’t want to bother with Li-ion batteries.
I measured with a power supply, but it seemed that 2 x CR123A would lead to huge overcurrent.
So I bought SKU 128084 from Dealextreme - which the sent to me incredibly quickly BTW, and I started to work.
First, this is a pair of step-up regulators. You need to saw them apart as the PCB is not scored or anything.
I soldered the red and black wires to the inner spring and the outside of the PCB, respectively. I cut some PVC tubing to support the step-up PCB in place, and used a slightly larger PVC tube to keep my AA in the center of the light.
The 5/8” and 3/4” PVC tube work fine for this - the 3/4” fits nicely into the 501B holder, and the 5/8” fit on the back of the pill and hold the tiny DX pcb.
There was no need to bypass the “regulator” inside the 501B (is there any???) , The light works fine, it is pretty focused, and in the center it shows the same amount of light as the much less focused 395 nm 2-AA light I have. That is with the original glass in place.
The 365 nm light shows the red fibres in 20 euro notes, which my 395 nm light does not.
One thing that you need to watch out for is the lens in it. I got a 365nm light with apparently a normal lens… it does a wonderful job of blocking UV light. You really need a quartz lens to get the most out of these… probably no lens is even better.
And watch out for coated lenses. If the coating is not engineered for the short wavelength it can block UV light very effectively.
Thanks for the reminder, I've totally forgotten that regular glass blocks UV very well. I guess I should build one without glass then.
Just curious, how about plastic lens and UV?
Usually it’s a better UV filter than glass…