ArmorMason Tactical 25.4mm-30mm Ring MountThe ArmorMason Dual Offset Rail Interface Mount Base is an aluminum rail accessory that adds two angled Picatinny mounting surfaces to a standard 20mm rail. It is designed to expand usable rail space on a handguard or upper receiver without modification to the host rifle. Versatile applications: Common applications include offsetting a magnifier or red dot for better eye relief, mounting a weapon light at an angle that keeps the tail switch within