EMG Helios Noveske N4 buffer tube question

I am trying to figure out if the buffer tube on the EMG Helios Noveske N4 GBBR is milspec or commercial spec. It has 5 holes like a commercial spec tube, but a non-slanted rear like a milspec tube. I don't have equipment handy to measure it. Does anyone know which type it is? Any help appreciated!