I dislike the way Prime's hood turns into a backpack. So I cut off the end of the piece that holds the hood onto his waist. It can easily slide back into place for his alt mode. I thought it would look cool as a shield. It fits well when his fist is folded in. He is also less bulky this way. It can also be put back in its original place in robot mode if you like it that way. Making the hood piece removable makes his transformation a little bit simpler.