Tactical side rail lock mounting scope mount base， durable aluminum construction， QD safety lock lever for quick installation. the side mounting， Top Picatinny rail for the optic， any scope, flashlight, or red dot can be installed onto this mount base. All steel dovetail side plate mount bases fit 105/102/74M/74U. The base is made of steel, Hard and Durable for use， Accepts a wide variety of side rail mounts， and comes with all mounting hardware.