Precision fast thread for 3/8" per turn elevation screw movement, lightest rapid-travel sight available, dependable elevation locking knob, solid one-piece 4" frame with 2.5" travel, windage micro-adjustments in precise and repeatable .002" increments, signature Isogrid design, unique split-block design for easy scope and pin attachment swapping, dovetail mounting block with detent, precise sight and accessory mounting (compatible with Sure-Loc accessories), cam-assist 3-axis leveling block included, black anodized finish. Note: custom knob kits NOT available for Phoenix.