The Daniel Defense AR-15 M4A1 RIII Upper Receiver Assembly is built around a 14.5 inch Cold Hammer Forged M4 Profile barrel with a permanently attached Daniel Defense Flash Suppressor, a GRIP-N-RIP Charging Handle, and mid-length gas system. It features a 12.5 inch lightweight RIS III rail-modeled after the revolutionary RIS II two-piece handguard developed for SOCOM-features M-LOK attachment for lighter weight while still offering M203 grenade-launcher attachment. 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 HandleFDE handguard