the xG3 came around… and our m31 and m36 were 1) named based on size - m31 was a 3mm x 1mm disc and m36 was going to be 3mm x 6mm cylinder, and 2) not “x-series” (not encased in injectable glass) i figured i should keep the xG3 within the “x-series” convention… so G gauss … and 3mm glass… so xG3.