You can find the Faxon Low-Profile Adjustable 3 Screw .625" Gas Block here.

The Faxon Low-Profile Adjustable Gas Block was designed for unparalleled control and reliability with a unique adjustment screw placement that prevents contact with carbon. The result is the gas block remains free from seizing or carbon fouling, ensuring consistent, reliable performance in any condition. The Faxon Low-Profile Adjustable Gas Block offers precise adjustability to fine-tune your rifle's cycling, recoil, and reliability, making it great for shooting both suppressed and unsuppressed. Made from high-strength steel, all Faxon gas blocks have a matching black luster Faxon barrels. The lightweight design is drilled through the middle of the profile. The gas block clamps on to the barrel using 3 Allen keys on the bottom of the block. These ultra-low profile gas blocks are perfect for any rail system.

Features:

• .625" Gas journal compatibility
• Ajustment screw never contacts gas port carbon, so it remains clean and operational without risk of seizing.
• Precision Adjustability: Control your gas flow to optimize your AR15's performance under any shooting condition, with 14 tactile settings from fully open to fully closed.
• 3 set screw mounting for added security
• Adjustment screw can be turned with either a 3/32" allen key or a flat head screwdriver
• 1" in length