I remember it being on the halo costuming wiki.
However i would recomend using the reach combat knife, as the H2 looks bad because they just couldnt do a good knife with the graphics not being as good.
@Toacrabman
Its there, I will try to make a Halo reach knife. I just want to have a knife to go here...
@zwave343
The action figure of the H2 ODST has a removable knife thats serrated on both sides, but I have see a vid of it on the H2 ODST, but to small to use.