The Seekins Precision Low Profile Adjustable Gas Block lets you fine-tune your rifle's gas system for smoother cycling and operation. Regulating the amount of gas used to cycle the action, or "tuning" the gas, is critical for suppressed shooting and load development. The Low Profile Adjustable Gas Block, when tuned correctly, allows faster follow up shots, target acquisition, and reliability of your rifle. Available Options:.625.750.875 Seekins Precision .875" Select Adjustable Gas Block 0011510067-F