ODIN Works 9mm Medium Profile Barrels are AR-15 barrels machined from 416 stainless steel for maximum durability. These ODIN Works 9mm Blowback AR9 Barrels are 1:10 button-rifled to reduce jacket deformation and create a more reliable barrel. They are 1/2-28 muzzle threaded and designed for blowback AR9 builds. Works with Colt or Glock lowers. Barrel lengths offered include 7.5, 10, and 16.1 inches.