1-piece mount 1 rings 4 long Fits 3/8 or 11mm dovetail 6 screws on base Ideal for magnum airguns and semi-auto rimfire guns Matte black BKL mounts have the unique ability to flex, giving them superior gripping power! Your mount may look like it's bending, but it's supposed to do that...it's grabbing and tightly holding your optics on your gun. BKL's patented Auto-Centering design overcomes problems caused by varying dovetail or rail widths.