MDT Elite 30mm High Scope Rings - Black - MDT Elite Scope Rings offer a solid, light weight mounting system for your optics. Made from precision-machined aluminum. MDT Precision Scope Rings are designed and manufactured to STANAG 4694 specification, also known as "NATO spec". This means the scope ring sits tight to the top of the scope base rail, with pressure being applied to the underside of the angled rail surfaces to maintain a solid interface (as shown below). This design also allows mounting on out-of-spec rails. The main body is machined on an automated seven-axis, high-end CNC machine tool Extra wide profile provides extremely stable mounting The bottom rail interface is machined at the same time as the scope clamp interface, guaranteeing all rings are square and parallel CMM checked to 1.5 millionths of an inch precision Machined from Billet 7075-T651 Aluminum - 1/3 the weight of steel with similar strength Extra thick clamp system will never bend, fatigue, or become loose with use Built-in bubble level on medium, high, and extra-high rings (No bubble level on low rings) Stepped base-to-cap interface allows the fasteners on one side to be tightened before making final scope alignment adjustments Six oversized #8-32 Grade 8 fasteners used for clamping the scope Sleek curves blend well into most scopes