Desert Tech's DT1x Reflex Sight was specifically designed for use with the MDR and MDRX. It comes with a specially designed mount that can attached directly to the gas block of the MDR - allowing the rifle to retain zero between caliber conversions. The mount also installs easily to the Picatinny rail or Weaver rail of other firearms. It features a crisp 3 MOA dot for rapid target acquisition and engagement, and 5 brightness levels allows the DT1x to be used in virtually any lighting condition. Features: Specifically designed for use with the MDR and MDRXAble to mount directly to the gas block of the MDR - allowing the rifle to retain zero between caliber conversions3 MOA dot, 5 brightness settings Desert Tech 1X Reflex Red Dot Sight w/MDR Mount. ACC0142