Solomark F60 60mm Guidescope 215mm Focal Length, F/3.6 Focal Ratio, Fully Coated w/Helical Focuser 60mm guide scope with bright, wide-field optics puts numerous potential guide stars in view so you'll never have to search for one! Very small and compact autoguiding system adds hardly any weight to an astrophotography setup and can conveniently be stashed in an accessory case between uses Compact mini guide scope designed for use with astrophotography telescopes up to 1500mm focal length Quick focus retractable tube with 1mm scale, can be locked in place. Precision non-rotating micro-focuser with 1/10mm scale. Fits standard Celestron, Skywatcher, Vixen & GSO type saddles.