I picked up a Nitro Duck Mega Reg 45/45 about a year and a half ago, I like the tank except for how heavy the reg is, and would rather have a screw in. I took it to a pro shop and asked them if they could swap that reg with a Nitro Duck X-Stream reg and they said that "The threads for the Mega Reg differ from the threads on other regs and so this would not be possible." As I were to understand it, the threading was made universal, but I'm no expert. Is this correct or did they just not feel like swapping the regs for me? Thanks guys!