8 Schmidt-Cassegrain Optical Tube Assembly Aluminum Optical Tube Celestron's premium StarBright XLT coatings 2032 mm focal length (f/10) 25 mm eyepiece included (81x) Visual back allows for use with 1.25 accessories 6x30 finderscope to help accurately find objects Star diagonal provides more comfortable viewing position when observing objects that are high in the sky Includes dovetail rail compatible with CGE mount