For increased comfort and versatility every MDX features our free-floating barrel with our custom handguard. These handguards provide a monolithic-like upper receiver platform and M-Slot compatibility. FEATURES Maxim Defense Hatebrake. M-Rax and M-Slot compatible handguard. Military grade materials. ALG Combat trigger. Radian charging handle and selector. Maxim SCW stock. Ambidextrous magazine release. Fully floated barrel. Last round hold open.  SPECIFICATIONS  Caliber: . . . . . . . . . . . . . . . . . . . . . . . . . 9x19mm Parabellum  Barrel Thread Pitch:. . . . . . . .. . . . . . . ½-28  Material Composition:. . . . . . . . . . . . . 7075 Aluminum & tool steel  Finish:. . . . . . . . . . . . . . . . . . . . . . . . . . . Nitride / Type III Anodizing  Barrel Length:. . . . . . . . . . . . . . . . . . . . 4.5” [114.3mm]  Overall Length:. . . . . . . . . . . . . . . . . . . 17.25” [438.15mm] (collapsed stock)  Weight: . . . . . . . . . . . . . . . . . . . . . . . . . 5lb 5oz [2.41kg]  Barrel Material:. . . . . . . . . . . . . . . . . . 4150 CrMoV  Muzzle Velocity:. . . . . . . . . . . . . . . . . . 1,150 FPS (Federal FMJ 124gr)  FUNCTIONS Receives all Glock 9mm pattern magazines, G19 and longer. MIL-SPEC+ coatings and materials. Fully and easily serviceable. Disassembles with common tools.