Our SIG MPX +10 extensions have become an instant hit — all the more so now that we have them in stock in RED. If you’re looking to maximize the capacity of your MPX and add a little “flash factor,” this is your part. For shooting your MPX in USPSA’s hot new “Pistol Caliber Carbine” division, this part is a must-have. Tactical shooters can’t ignore adding 10 more shots with such a small increase in bulk. 100% CNC machined from billet aluminum, made in USA