N/A Huma Air Belleville washers?

To answer my own question, it's 15mm for the standard Huma Air regulators. I think the smaller ones are for the external type regulators without the Huma Air housing.

I bought both 60-115 bars and 70-150 bars for both of my guns with different tunes.

I just received the washers and it doesn't come with any instructions at all. Does anyone know if the orientation would be the same as the stock? I tell you, shopping at the Huma Air website is quite frustrating. Some of the products they sell lack basic instructions. I understand it's mostly for the DIY people but something as simple as washers orientation should be included.

Ok, I think I may have found the answer from this YouTube video. Yes, I'm aware that different regulators have different washer configuration but the configuration shown below is exactly the orientation for the Taipan Veteran with the high pressure washers.

I've been playing with the Standard Veteran .25 for a bit with the medium pressure Belleville washers installed. The washers are rated for 70-150 bars and I have the regulator set to 100 bars. From the high pressure washers, which are rated for 100-170 bars and also set at 100 bars, the gun has gone from 3 bars per shot down to only 2.5 to 2.75 bars per shot with the properly rated washers. This means it gained about 5 to 10 shots on a full 250 bar fill for the same tune of 44 FPE.

I don't really know how to explain it other then it's obvious that the washers run well within its rated range pressures are more efficient. One thing I noticed is that running the high pressure rated washers at such low pressures, the piston of the Huma Air regulator is almost bottomed out and is very close to the retaining C-clip. This is most likely why the Huma Air instructions warns about setting the regulator too low... Because the piston will start putting pressure on the C-clip at the bottom. This means that running them so low really reduces the springs' range of motion which most likely causes inefficiencies with how quick or slow the regulator closes back up once the pressure in the plenum drops after a shot is taken. Again, I don't know exactly what's going on... I just know I gained at least 5 more shots for the same power tune.