Quoting Joel Szasz
The things on the back are meant to be maneuvering thrusters, similar to those on Geno Breaker, but based off of the units mounted on Iron Kong Mk-II. I don't see to much of this guy, except on Zoids Legacy/Saga II, so kudos to you for giving this guy some limelight. Pretty good, and lets keep in mind that you are the only one to attempt a Lego Proto Breaker (that I know of). Might I suggest posting a screen shot of Proto Breaker when you get the chance, so that viewers can compare this guy to the real deal?
on the subject of the thrusters, i have to disagree. if you look at the ends of both, iron kong thrusters have asquare projection on them. whereas proto breakers' are smooth all the way up :)
