It looks like the modded engine. JP had a situation with the .21 buggy engine. People bought the FX05 (or whatever the y were called) thinking they were modified engines but it turned out there were just JP's version of the P5. No different from Rex, Top or Nova. Then there is the "modified" version that comes with the black case and modded internals for much more. From what I understand JP has stopped producing the non-modded buggy engine because there was so much confusion. Since your engine does have the black casing, I would assume it is the "modded" version but who knows. I've been told the Mugen X12 is as fast (if not faster) for less money.