Is That Jarhead?

For years I thought Jarhead was just a wise guy talking smack to the rest of us. Now I find out that the marines have "knife hands"? What the heck is that? I just thought they liked to shoot big ol' guns and stuff. Instead they've got lethal hands that could double as party tricks. Cool.

(And why does it sound and look like these two guys are in the maintenance closet of a club?)