Browning X-Bolt Scope Mount System 1" Securely mounted optics are essential to the accuracy and precision of any rifle. To ensure the new X-Bolt has the most stable mount possible, this system features an all new X-Lock scope mounting system that uses four screws per base, replacing the traditional two-screw system. The scope bases being secured at all four corners rather than only held at the center of the base enables more accurate placement of the bases on the receiver. This revolutionary new X-Lock system holds the base tighter to the rifle than ever before. Features: Integrated Scope Mounts unitize the ring and base into a single unit machined from 7000 series aluminum and eliminate alignment problems and possible loose connections between bases and rings Use the .400" Low ring height for scopes up to a 44mm objective with a standard barrel contour Use the .500" Medium ring height for scopes up to a 50mm objective with a standard barrel contour Use the .600" High ring height for scopes up to a 56mm objective with a standard barrel contour 1 Inch diameter Matte Black Important: Compatible with Browning X-Bolt rifles only.