This is actually a H2O, just externally painted in FDE Cerakote. This M4 is set up for a leftie. Only the visible areas of the bolt carrier are painted in FDE, everything else is Np3 plated.
One cool feature is the RMR spacer that is a 10mm spacer. This raises the RMR up enough to use the optic in the middle position of the collapsible stock comfortably. The spacers come from Reptillia in a few different heights. I had to grind the screws down to make them the correct length to fit the Scalarworks Sync mount.