This high-quality, integrated scope base/ring system provides an additional 20 MOA of elevation so you can dial in more drop on your scope before you have to start "stacking" MOA/Mils. Securely mounted optics are essential to the accuracy and precision of any rifle. To ensure your X-Bolt has the most stable mount possible, this system features the X-Lock scope mounting system that uses four screws per base, replacing the traditional two-screw system. Securing the scope bases at all four corners rather than only held at the centre enable more accurate placement of the bases on the receiver and holds the base tighter to the rifle than ever before.