Astromania 12.5mm Illuminated Reticle Plossl Telescope Eyepiece - for perfectly guided astrophotos Adjustable image and reticle focus and adjustable LED illumination. Requires three button cell LR1130 (Not Include). This is steplessly adjustable via a knob on the side of the eyepiece. There is also a separate dioptre adjuster for you to be able to bring both the star and the crosshairs into focus simultaneously. Bright high-contrast views with a 40-degree apparent field of view and 11 mm eye relief,comfortable eye relief. Reticle eyepiece comes with dual crosshair - really clean view for you to observe your target, filter thread provided. Excellent for accurate polar and go-to alignment, and for centering guide stars for astrophotography. High quality 12.5mm focal length Plossl eyepiece with red LED-illuminated double-line crosshair reticle.