National geographic CF700SM black carbon fiber telescope with phone adapter. Embark on a fascinating adventure through our solar system and beyond with National Geographic’s 70mm telescope. This refractor features unique carbon fiber styling that gives it a rugged edge and a 70mm aperture that will perform well in lunar, planetary and deep-sky observing situations. Its manageable 700mm focal length makes it highly portable and results in a versatile f/10 focal ratio that offers both wide fields.