The XD OSP Slide Assembly includes an OSP-cut slide assembly for an XD 4″ 9mm pistol along with a Springfield Micro footprint optics-mounting plate. It is designed to convert an XD 4″ 9mm to an XD 4″ 9mm OSP while utilizing the original pistol’s barrel and recoil spring system. With this assembly you can easily swap out the slide on your 4″ 9mm pistol to gain OSP optics-mounting capabilities.