we have build and very much tested under real sky a high quaity 20" F/8.5 Maksutov Cassegrain ( Rumak Design) , optics made by Santel in Russia, Mechanics made by Matthias Wirth in Germany. The beast is now for sale . It comes with a set of tube clamps, dew cap, 3" Starlight Feather Touch extension, meniscus heater, main mirror vent, 2 maintenance flaps, handles to move tube, and 2 sets of losmandy dovetail holders for large guiding telescopes. The optics are very smooth and have excellent spherical correction. The lens is broadband multi-coated on both sides. The cooling behavior is excellent.

Item condition: used Item with possible small cosmetic deffect, but every function works perfect