The new X-Ring Open Sight .22LR barrels are machined from 6061-T6 aluminum. The premium X-Ring barrel has been designed to make your Ruger(R) 10/22(R) rifle lighter and significantly more accurate. The X-Ring barrel fits all Ruger 10/22 receivers and most aftermarket 10/22 style receivers. Accuracy is enhanced by a rifled chromoly steel liner with a polished 11 degree crown. The X-Ring Open Sight barrel comes with an adjustable green fiber optic rear sight and green fiber optic front sight. Features : Fiber optic sights 1/2X28 thread pitch "1:16" rifling,