Apochromatic refractors produce the sharpest and highest quality images of all telescope systems thanks to their shadow-free, textbook-like diffraction pattern. The Skywatcher high-end Evostar 150ED Apo refractor contains a doublet lens with a lens made of particularly low-index ED glass and a matching crown glass element. Each glass-air surface of the optics has been given an exotic, metallic anti-reflection coating to achieve a high, maximum light transmission of 99.5%! The groundbreaking Skywatcher “Metallic High-Transmission Coating” (MHC) is the highest quality optical lens coating in its class. A 0.85x reducer / corrector tailored to the telescope is also available as an optional accessory. Lens diameter: 150mm Tube length: 1280mm Focal length: 1200mm ( f/8) Dual-Speed 11:1 2” Crayford focuser Tube rings & 45mm Skywatcher / Vixen standard dovetail bar Solid aluminum carrying case !Power supply and batteries are not included!