Lightweight integrated scope mount system for the X-Bolt rifle, unitized base and ring, 7000 series aluminum. Integration means stability. Browning's Integrated Scope Mount System unitizes the ring and base into a single, ultra-rigid unit. Machined from 7000 series aluminum alloy, they eliminate alignment problems and the possibility of a loose connection between the base and ring. .500' Intermediate height. Assuring accuracy. 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, it features an all new X-Lock scope mounting system that uses four screws per base, replacing the traditional two-screw system. The benefits are obvious, with the scope bases being secured at all four corners rather than only held at the center of the base, allowing for 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. Two pieces. Black.