UCLp
18 and 20 both in the UCLp, but not in the glass UCL.
Thanks :+1:
Chris will cut custom sizes in the UCLp if you ask him. 
I have a couple of their UCL lenses I got for my M1s, definitely high quality products, better than the cheaper AR lenses commonly available.
ok, so, this L6 and the lens question…
With an Thorfire S70 lens it makes 5740.8 lumens
With an Klarus G35 lens it makes 6168.60 lumens
With no lens at all it makes 6523.95 lumens
So there ya have it. The S70 lens is costing it 783.15 lumens while the Klarus G35 lens is only losing 355.35 lumens. This is all on the same LiitoKala 5000mAh cells without recharging them, I took the S70 reading last night on fresh cells, the no lens reading first this morning, then the Klarus reading last.
I also talked to somebody that has used the SIR404DP MOSFET quite a bit lately and found them to be finicky, easily damaged by heat in the re-flow sequence. So I’ll be pulling the 404 and putting an 800 back on.
People ask why I pay $8 for an UCLp lens, with a lot of effort going into making a 6500-7200 lumen light it sucks to lose 780 lumens to the lens! Cutting that loss as much as possible is worth the price, considering the FET itself can be as much as $4, why not let the light out with the right lens?
I’ve shown a light to my Dad before after putting the UCLp lens in it (without saying anything about the lens swap), no kidding he tried to put his finger in the reflector declaring I’d forgotten to put the lens in! Then the astonished look on his face when his finger hit the lens, like that last step you thought was there and about fall down when it’s the floor instead of another step. I myself have completed a build and thought the same thing, you see the emitter so clearly down in the reflector that you have to tilt the light around and try to catch a reflection off the overhead light or a window, it’s really just amazing how clear it is.
Awesome , i would like to see that haha 
With the 91K resistor on the switch LED’s and the new 20mm driver now having an SIR800DP FET on it, I’m still only getting 5754.6 lumens with the Klarus lens on and 6272.1 with no lens at all. So I’m nearly 1000 down from when I first built this light. In this instance, the lens itself is robbing me 517.5 lumens. Guess I’ll be getting an UCLp and see how that works out…
On the plus side, it’s working fine with the lighted switch. 
Isn’t UCL better than UCLp ?
There may be a size issue with their UCL in glass. The biggest is 55mm. I don’t know if they can cut a bigger size or not.
In the UCLp, they have a 68mm listed.
So this driver and the previous one are both pulling the same amps from the same batteries, yet the 17mm had more output?
Maybe there is a difference in driver efficiency?
Maybe there was a difference in amp draw at the emitter?
It’s also possible your P2 emitter has suffered a bit of damage over time with such high current going through it.
I’m assuming your light box and meter are all setup the same.
Just spit balling ideas here.
Yes, here is what Dale said earlier.
Get the UCLp “G” you won’t regret it.
UCL 98- 99%
Borofloat 94%
(.095” thick) A/R Glass 99%
UCLp 97% BONUS 99.999% chance of not shattering and taking out you reflector!
Thanks for your answers .
Kwb unfortunately shipping is the deal breaker everytime i try to get something from the US , will have to make a big order some time 
What is the “g” version?
Kawi is being silly. UCL means Ultra Clear Lens. UCLp means Ultra Clear Lens plastic, actually it’s acryllic.
Borofloat is glass, so of course it can’t be UCLp. Just sayin…
Borofloat is actually a different type glass, the UCL is water white. 98-99%.
Borofloat is 94% and made of borosilicate glass. The Borofloat isn’t AR coated.
“G” refers to giorgoskok
I see.
I’m gonna get the uclp and check it out. Use the stocker as a spare. :+1:
I think the meds may be gettin to me, I first posted this on the C8 thread, then realized I was somewhat off base… 
Edit: Can you spot 9 lights and a laser? lol That’s a tiny corner of the bottom shelf, with 2 full shelves above it!