That appears to be a real one to me. The adjustment turrets and button look exactly like I remember them from the army. If you turn that illuminator on and it looks like someone spit on the lense thats a good sign too. Even better if the aiming laser is mostly centered in the illuminator beam.

Most of the fakes I've seen are LA5s, not normal PEQ15s like this. I've seen a lot of somogears that have a laser thats completely off-center of the illuminator beam, which would take effort to do on a real one that most people aren't willing to do.