Arisaka Defense Optic Leveler, Small, (2) Piece Optic Leveling Tool, Anodized Finish, Black OL-SMALL The Arisaka Optic Leveler is an inexpensive" easy-to-use tool for leveling scopes mounted in rings or one-piece mounts. The base plate sits on the Picatinny rail or one-piece mount just below the turret cluster of the scope" and then the matching wedge is inserted from the side. As the 11 degree ramped surfaces of the wedge and base engage" the top of the wedge rises upwards and contacts the turret cluster" automatically leveling it. This product includes the leveler base and small wedge" which requires a space between the rail/mount and turret cluster from 0.190" to 0.730".