Christensen Arms 810-00042-01: Whether chasing distant targets or trophy game, the Tactical precision CNC-machined rings feature 6-bolt caps and a removable anti-cant bubble level to ensure shot-after-shot accuracy and unmatched performance. Standard 1/2\" nut attachments to ensure secure and consistent clamping force. Fits Picatinny style mounts and are NATO-STANAG compatible. Includes removable anti-cant bubble level system to ensure your rifle is perfectly level for shot-after-shot accuracy.