Desert Tech MDRX Forward Eject Semi-Automatic Centerfire Rifle can be converted within a few minutes to any of the available calibers (components sold separately). Built to survive the harshest military conditions. It is ultra-compact, perfectly balanced, intuitively ergonomic, easily concealable, and fast to deploy. The MDRX can go where you go. All MDRX rifles and conversion kits now include "Free Flow" gas valve technology, improving gas flow, minimizing leakage, and reducing gas block contamination. FeaturesCaliber ConvertibleMDRX Passes Mil-spec Drop TestsReengineered Trigger with Less Creep and Less TravelGas-Block Passes Mil-Spec Water And Mud Immersion Testing