Strange, I just compared one we just got a month or so ago to one from at least 2 years ago or so and both are exactly the same except the shrink wrap on them. What dimensions are you getting? I'm getting 3.75mm for the Xenon tube and around 4.8mm including the wire that runs down the side of it. At the widest the wires that run down the barrel are around 2.6-3.8mm depending on how the wires are heat shrunk. Either way this should be plenty to fit down the minimum 6mm barrel we use (need that 6mm for airsoft) and I doubt there will be a new barrel just for IR like we did in the past. I'll see if I can get an update on if there is two different barrels ok?