DESC: Guide long-exposure photographs or CCD images with this ideally suited 80mm achromatic refractor (910mm f.l., f/11.3). This achromatic refractor has a 1.25" cast-metal focuser and a focus tensioning knob to keep the drawtube secured firmly in place when your guiding eyepiece or CCD autoguider is attached. Mount the guidescope atop your main telescope via the aluminum mounting bar and included attachment bolts. This package comes with a 1.25" prism star diagonal and 5mm Ultrascopic illuminated reticle eyepiece, which provides a double-line, brightness-adjustable reticle and 182x magnification. Also included are a pair of aluminum guide scope rings with nylon adjustment screws.