Quick-release lever-lock system clamps solidly to flattop rail and will not work loose even under heavy recoil-the more force acting on the lever, the tighter it locks. Depress the release tab to swing the lever open, and the mount easily lifts off the rifle. Adjustable with a flat head screwdriver or even a coin for an ultra-secure, no-slip fit on almost any Picatinny or Weaver-style rail, including over- or under-sized commercial rails. Lever may be configured to lock to the front or the rear to suit the operator's preference. Large locking bar on the side of the mount engages the maximum amount of rail area, while the crossbolt and two integral locking lugs ensure rock-soli Mfg: American Defense Manufacturing SPECS: 6061 T6 aluminum, hardcoat anodized, matte black. 4A 1/2" (11.4cm) long. Each ring covers 1" (2.5cm) of scope tube length. Height measured from top of rail to bottom of scope body (both models): .890".