Primary Arms Quick Detachable Flip To Side Mount - Standard Height, (Black) MAGNIFIER MOUNT: Perfect for placing a magnifier behind red dots, microdots, and reflex sights. SIZE: Fits all Primary Arms magnifiers and other brands with a 30mm mounting surface. FLIP-TO-SIDE: Simply pull the magnifier to the rear to unlock the mount and choose between centerline and off-centerline positions. QUICK-DETACH: The quick detach throw lever style mounting system makes it easy to attach or remove the entire unit from your firearm.