Machined from 416 stainless steel for optimum durability and longevity. Does NOT have forward assist serrations but does feature dust cover notch. 100% increase in bearing surface for smoother operation, improved alignment and lower wear in the upper receiver. Recommended for competition and recreational use. To further enhance the performance of the JP Low Mass Carrier, we recommend the use of the JP Low Mass Buffer. (Low Mass Operating System) reduces felt recoil and less movement during cycling to aid in shooter being able to stay on target. This carrier has 100% bearing surface to aid in smoother operation.