Specifically designed to fit X-Bolt rifles chambered in the longer action required for Remington Ultra Magnum calibers. Out of the box, the X-Bolt rifle is an incredible shooter capable of jaw dropping accuracy. For those of you looking to reach out a little bit farther, this high-quality, precision scope ring base provides you with a solid lock-up to your action and an additional 20 MOA of elevation so you can dial in that much more drop on your scope before you have to start "stacking" MOA/Mils. The integrated bubble level makes leveling the crosshairs in your scope easier and helps eliminate cant error for improved accuracy.