The Endomag system does NOT come with a PMag. You must either add on one to your order or use a Gen 2 or 3 PMag that you already have  

The MEAN EndoMag® is a magazine insert that converts your Gen 2 or Gen 3 5.56/.223 PMAG® housing into a 9mm magazine to use with a standard AR lower and 9mm upper with a Glock or Colt variant 9mm BCG.

EndoMag features:

• Quickly and easily change calibers from .223/5.56 to a caliber associated with the EndoMag in a Magpul 30-round 5.56x45 PMAGsⓇ (Gen 2 and 3)
• Functions as a magazine!
• No magwell adapter needed!
• Keep your standard 5.56 Multi Caliber lower receiver!
• Comes fully assembled.
• No tools required.
• Keep all your PMAGsⓇ in use, no need to buy additional or specific 9mm magazines.
• Keep your muscle-memory reload-training the same between calibers! Same magazine, same draw, same feel.
• No learning curve when reloading because it is the same magazine you already use!
• Use most of your PMAGⓇ accessories: i.e. mag pouches, storage racks, decals, caliber indicators, etc.
• Not a picky eater. Shoots all 9mm munitions. Hollow points included.