Explore Scientific 10-Inch f/4.4 Dobsonian Reflector Telescope Black. Its fast f/4.7 focal ratio and 1200mm focal length make it an ideal choice for deep-sky observing and astrophotography delivering wide-field bright images with shorter exposure times. Specifications for Explore Scientific 10-Inch f/4.4 Dobsonian Reflector Telescope: Manufacturer: Explore Scientific Color: Black Magnification: 48 x Objective Lens Diameter: 254 mm Objective Aperture: 254 mm Focal Length: 1200 mm Focal Ratio: f/4.4 Finderscope: Red Dot Finder Optical Coating: SiO2 overcoat Battery Type: Lithium Ion Features of Explore Scientific 10-Inch f/4.4 Dobsonian Reflector Telescope Massive Light-Gathering Power - The large 254mm (10-inch) primary mirror captures more light allowing users to explore deeper into space and view fainter celestial objects with enhanced clarity and brightness. Fast Optics for Deep Sky and Imaging - With a 1200mm focal length and f/4.7 focal ratio this telescope delivers wide bright views and enables shorter exposure timesperfect for astrophotography and deep-sky observation. Easy-to-Use Dobsonian Mount - The smooth Dobsonian mount is simple to operate for beginners and experienced users alike with a spring-based tension system that keeps the optical tube balanced when using additional accessories. Package Contents: Explore Scientific 10-Inch f/4.4 Dobsonian Reflector Telescope 23mm Plossl Eyepiece Red-Dot Finder Explore Scientific ES-ON25447: 10-Inch f/4.4 Dobsonian Reflector Telescope Black