| Ort der Herkunft |
Sichuan China (Mainland) |
| Marke |
Qunhui |
| Modell-Nummer |
40A |
It is used for focusing mount of astronomical telescope , requiore high concentricity the inner bore and excircle , high precision milling grooves , high run of rays magnification times , and the surface is treated by anticathode oxidation , which have anti-corrosion and non-fading advantage.