Geissele SAG 5.56 Suppressor Alignment Gage (10-259-F) is a precision-engineered tool designed to ensure proper suppressor alignment with a firearm’s bore, reducing the risk of baffle strikes and enhancing accuracy and suppressor longevity. Caliber: 5.56 mm / .223 Length: 15? Material: Hardened steel ground 0.002? under nominal bore diameter Straightness Tolerance: Finished to within 0.001? over its length Manufactured in: U. S.A. Geissele SAG 5.56 Suppressor Alignment Gage 10-259-F