About this item EXPERTLY MATCHED GLASS: The EvoStar series features a matched doublet objective including one synthetic fluorite element, providing excellent color correction for visual and photographic uses OUTSTANDING COLOR CORRECTION: Using the finest quality glass and proprietary Metallic High-Transmission Coatings (MHTC), EvoStar refractors produce tack sharp images with accurate color and minimal aberrations EVOLVES WITH SKILL: No need to replace this telescope as your skill set evolves. Whether you’re a seasoned astrophotographer or a budding novice, EvoStar refractors are versatile enough to use as your primary optical tube as your skill-set improves 10:1 DUAL-SPEED FOCUSER: No matter the eyepiece or camera, finding focus is a breeze with this 10:1 dual-speed Crayford-style focuser       Optical Design    ED Apochromatic Refractor         Optical Diameter    100mm         Focal Length    900mm         F/Ratio    F/9         Highest Practical Power    200x         Faintest Steller Magnitude    12.7         Finder Scope    8X50         Focuser Diameter    2" dual speed, crayford         Diagnol    2" 90 deg. Dielectric Diagonal with 1.25 inch adapter         Eyepieces    LET 2"-28