Versatile adapter!
Celestron's 1.25-inch visual back is used to adapt the threads on all Schmidt-Cassegrain telescopes for use with 1.25-inch accessories items, such as diagonals, and for straight-through viewing with eyepieces. The visual back comes standard with all Celestron 5-, 8-, 9.25- and 11-inch Schmidt-Cassegrain scopes and fits any SCT that takes 1.25-inch oculars.