Knob For M2.5 Screw

I had an iris adjustment knob break off of an old lens, but found that an M2.5 screw just so happened to fit perfectly in its place.  So I modeled up a quick plastic knob that I could screw onto the head of the screw to give myself a more ergonomic surface to grip than the bare screwhead.  This is sized so that you should be able to just grip it gently in a pair of pliers and screw an M2.5 screw right through it from the top, the screw will cut its own threads