I just picked up a used XD .40 Service for a great price. It came with 2, 12 round mags. In the case was a magazine spacer (factory XD that fits on the mags that I have). From what I know, the 12 round is the largest capacity mag that will fit in this model (aside from the aftermarket 20 rounders). I'm thinking it was put in the case by mistake. Anyone know about this?