The Daniel Defense AR-15 MK18 RIII Pistol Upper Receiver Assembly is unmatched in size, weight, and performance, and features the Daniel Defense RIS III rail. The lightweight RIS III rail-modeled after the revolutionary RIS II two-piece handguard developed for SOCOM-features M-LOK attachment for lighter weight. The 10.3 inch Cold Hammer Forged barrel is the same length in use for the MK18 upper most commonly used for CQB operations. Its independently ambi GRIP-N-RIP Charging Handle accommodates left- and right-handed shooters. All Daniel Defense complete upper receiver groups come standard with an M16 profile bolt carrier group. FeaturesCold Hammer Forged BarrelPinned Low Profile Gas BlockGRIP-N-RIP Charging Handle