SM34004- Add more to your gun quickly and easily with the Sightmark CJRK Tacticle Riflescope Mount. Named in memory of former Sightmark colleague Caleb John Richard Koszewski, the Sightmark CJRK Riflescope QD Mount combines a rock-solid platform for mounting high-power riflescopes on flat-top rails with the versatility of a quick-detach tactical mount. Featuring an innovative cantilever design, the Sightmark CJRK Rail Mount provides proper eye relief and the ability to easily return to zero on a variety of AR-15 platforms.