The Primary Arms SLx 3X Micro is a small, light 3x magnifier for use behind a red dot or a compatible 1x prism. It weighs only 150 g, and its small size leaves more rail space than traditional magnifiers.
21 mm objective, 7 mm exit pupil and 61 mm eye relief. Field of view is 11.7 m at 100 m. It fits Primary Arms two-bolt magnifier mounts; the mount is sold separately.