Daniel Defense 08806027055: The Daniel Defense M4A1 features the M4A1 RIS II, which has been in use by US Special Operations Command (SOCOM) for the Sopmod II Weapons System since 2005. The M4A1 features a 14.5 Cold Hammer Forged M4 Profile barrel with a permanently attached Daniel Defense Flash Suppressor. This rifle also comes with the rugged and comfortable Daniel Defense Buttstock and Pistol Grip. The M4A1 CA Compliant model ships with a Daniel Defense magazine with a 10-round limiter installed.