Bijdrage ik wil Wind doublet telescope varkensvlees Parel Wereldvenster
RVO Horizon 60ED Doublet refractor - BBC Sky at Night Magazine
Amazon.com : Sky-Watcher Evolux 62ED Doublet Apo Refractor Telescope- Compact and Portable Optical Tube for Affordable Astrophotography and Visual Astronomy, White (S11305) : Electronics
APM Telescopes. APM Refractor Telescope Doublet ED Apo 152 f/7.9 OTA with 2.5" focuser