Adjustable Precision Diopter Sight. Rear diopter sight and hooded front sight. Designed and Engineered in the U.S.A. Delivers repeatable micrometer sight adjustments. Allows user to rotate front and rear sight for shooting in cant position. Compatible with 11mm dovetailed receiver. Comes with non-shooting eye blinder that attaches to rear sight. Includes: Fixed sight blades and rotatable sight blades (sizes 3.8mm, 4.0mm, 4.2mm and 4.4mm).