The DS Arms Low Mass ESC - Enhanced Sand Cut complete bolt carrier group is the pinnacle of AR15 - M16 bolt carrier group production. They took their standard Mil-Spec bolt carrier group and upgraded with real world no-nonsense features that make sense, not just make it flashy! First and foremost, they looked to their roots in the FAL Battle Rifle and incorporated L1A1 style sand cuts on the all of the load bearing surfaces of the carrier. These sand cuts allow any sand, dirt or debris that may have gotten into the action to easily be cycled out. DS Arms machines these assemblies using the latest manufacturing techniques, material and finishes. The carrier is machined from 7075 T-6 A Mfg: D.S. Arms