The CX4's using the PX4 and 92/96 mags are for the 9mm and .40 cal CX4.
The .45 cal CX4 uses the same mag (8045) as the Beretta or Stoegar Cougar 45 and no one but Sierra Papa makes hicap mags for them.
I have 3 of them and they are very well made. I have only shot about 400 rounds thru them but I have had no problems.
My CX4 45 is my favorite carbine to shoot but the 8 round mags were drving me crazy, These mags are money well spent.
Now I need to buy a Stoegar Cougar 45 to share the mags with.