D70mm refractive objective lens devised for DIY astronomical telescopes, perfect for enthusiasts and hobbyists. Available in multiple focal lengths: 300mm, 360mm, 400mm, 500mm, 700mm, 800mm, and 900mm, allowing for versatile viewing options. Features a double separation structure with a single-sided blue film optical coating for enhanced light transmission and clarity. Ideal for optical experiments and telescope upgrades, ensuring superior performance in stargazing and observations. Package includes 1 lens; please note that any visible scratches in images are due to shooting angle and light, not lens defects.