50Mm guide scope finderscope with double helical focuser for astronomical telescope 183mm 1.25in focal length ratio guidescope This solidly built 50mm Guide Scope will help guide you to capturing higher quality astrophotos. With its 50mm lens and smooth helical focuser, the versatile 50mm Multi-Use Guide Scope with Helical Focuser is an ideal addition to any astrophotographers collection of gear.Features:6-point screw bracket.183mm focal length.This guide scope is made of quality material, sturdy, lightweight and practical.50mm guide scope with bright, which offers 1mm precise adjustment, helps you quickly finder the target in the telescope.Comes with a bracket that fits all kinds of telescope, easy to install.Nice accessory for astronomy lovers.Removable dovetail bracket.For use with astrophotography telescopes.Compatible with popular CCD guide star.Quick focus retractable(20mm) tube.10mm focusing range with micro-focusing helical focuser.Specifications:Material: MetalFocal Length: 183mmInterface: 31.7/1.25inObjective lens: 50mmCoating: Fully multi-coatedItem length: 235mm / 9.3inItem Weight: 580g / 1.28lbPackage Weight: 800g / 1.76lbPackage Size: 280 * 140 * 140mm / 11.0 * 5.5 * 5.5inPackage List:1 * Finderscope