Description
1PC Dia. 30 mm Do ublet O b jective Lens for DIY Refracting Achromatic Telescope Suitable for DIY binoculars, viewing mirro r s, star finder, etc. Coating|: multilayer film 400-700nm Combined image quality: 1/4-1/8 Diameter tolerance: +0/-0.12 mm Center thickness tolerance: ±0.2mm Focal length tolerance: ±0.1% Finish: 60/40 eccentric: 1'