Beretta APX Compact Magazine Spacer (C SPACER)

I ordered two of these and two 15 round magazines thinking one spacer was needed for the 15 round mag to fit my APX Compact, but it needed two spacers? Doesn't make sense to me. The 15 round mags are longer than I expected. Stamped 15 but I didn't load to capacity to verify. Maybe I ordered or received the wrong ones.

In another review I purchased 15 round APX Centurion magazines to be used in a Beretta APX Compact pistol. At that time I also purchased the Beretta Centurion mag spacers, they really do work great. When the magazine is installed with C spacer, mag locks in with no movement, and grip has solid feel. Another win for Beretta, and their customers!