The MICRON Caliber conversion kit used to convert your MDRX Rifle to the 11.5″ Micron. This kit is designed to convert your side eject MDR or MDRX Rifle from any caliber to the 5.56 NATO / .223 Rem Micron.
Desert Tech MDRX Conversion Kit, Side Eject, 5.56 NATO, 11.5″ Threaded Barrel, Flat Dark Earth, 30Rd, 1 Magazine MDR-CK-B1130-SE-F