We as XTech Tactical believe that standard capacity magazines are a Constitutional right in the US. This kit is intended for when you move, your state laws, or your legal status changes in a state with 10 round limits. The kit allows you to convert your MTX 365 +0 to the standard +3 9mm. Just follow the instructions and remove the spacer along with the factory spring and follower and replace them with this kit to turn your 10 round magazine into a 13 round magazine. In order for this to work you must already have the MTX 365 Plus 0 Extension mounted on your 10 round magazine. Enjoy your freedom! WILL NOT SHIP TO CA, MD, MA, NJ, NY, DC, CT, HI, WA or INTERNATIONAL.