Huma Gen 3 Impact regulator valve disk install help

Replacing my 2nd reg on my Impact M3 with a Huma Extra-High pressure Reg. The reg came with two different delrin "valve disks" that go between the the head of the piston and the valve adjustment screw. One is flat on one edge and the other has a crescent shaped cutout. The instructions only show what looks like one disk installed and not two. So, if it's one, which one? Or, do I install both? If so, in what order? I'll attach some photos for reference. Any help would be appreciated.

huma valve discs.jpg
huma reg .jpg
 
Only use one. The shape of the cut is not critical. What matters is that the disc is a proper slip fit down in the regulator body so it cannot move around. Since you have 2, my recommendation would be to drop each one in. If either one is a loose fit, discard it and use the one that fits better.

They are probably cut with a die so there may be no difference but since you have the opportunity to pick a favored one, you might as well.