Springfield Armory : PG-XD+
Springfield Armory XD Series Extensions
These units replace the magazine floor plate and internal floor plate on the 9mm (13 round only), 40 S&W, 375 SIG and the 45 GAP. These units will add approximately 1 inch in length and additional capacity. NOTE: These extensions will not work with the 10 round 9mm magazines, the XDM frame or the Mod2 frame.
*Check your state and local laws regarding magazine capacity restrictions.