spec: Primary mirror: 200 mm, coated 197mm, 1.9 kg， glass thickness 27mm mirror with cell: 2.8 kg primary mirror: focal ratio: f/4 mirror to inner wall 13.5 mm mirror face to back of tube : 50 mm secondary: 63mm nom. (minor axis). Minimum required is 54 mm tube 230 mm outer OTA: 8.5 kg, including lock rings and dovetail, length 730mm nom. as 100% illumination is around 9.3mm, this configuration is mainly for visual. of course won't stop you to go for astrophoto, with appropriate sizing of secondary, eg 73mm(minor axis) The mirror has some minor polishing marks at 70% radius, at r =14 cm, width 1 cm i guess those are left behind from figuring it to parabola Slight hill at centre, radius 5 cm coating is a bit opaque, guess it is over 20 years ago. 80 to 85% reflectivity Focuser: JMI 2 inch, with motorfocus , jmi2 secondary holder: collimation: not easy, but do-able first make alignment by visual, then use the laser collimator. btw it's a test of laser colli...