Samson Low Profile Gas Block .625 Diameter Black. Samson made these Rifle Gas Blocks from 303 stainless steel to handle whatever you subject them to and they're a great choice for those who need Rifle Gas Blocks that can securely attach a variety of accessories. Each Samson .625in Low-Profile Gas Block includes four 10-32 set screws that can even handle multiple Evolution accessories you attach to your rifle. Ensure your rifle is fully serviceable and equipped with the gas blocks your rifle needs by equipping this Samson Low Profile Gas Block. Specifications for Samson Low Profile Gas Block: Manufacturer: Samson Color: Black Gas Block Journal Size-Diameter: .625 in Package Contents: Samson Low Profile Gas Block Samson 04-06005-01: Low Profile Gas Block .625 Diameter Black