Solomark 12.5mm Illuminated Crossaim Reticle Plossl Telescope Eyepiece (Not Include the Batteries) Multi-coated 4-elements Plossl design - excellent color correction and sharpness Steplessly adjust the brightness of the dual crosshair reticle - just rotate the switch to put it on, shut it off and adjust the brightness - allowing you to ideally adjust it to the brightness of the guide star Fold-down rubber eyeguard Threaded for standard 1.25inch astronomy filters Compact size and all metal construction Comes with eyepiece caps-proect the eyepiece from dust and moisture