Item Number: HN-6001R-NFits: Henry Big Boy Carbine, Standard and X Series in .44 Magnum, .45 Colt with Round BarrelFits: Henry Big Boy X Carbine in .357 Magnum with Round BarrelPicatinny Compatible RailCNC Precision MachinedAircraft Grade AluminumHard Coat Anodized FinishDIY InstallationMade in America for an American Made RifleHenry Big Boy Carbine, Standard and X Series in .44 Magnum, .45 Colt with Round BarrelHenry Big Boy X Carbine in .357 Magnum with Round BarrelDesigned to work with Henry Rifles with Steel Receivers and Round BarrelsXS Lever Rails are Caliber Specific