Orion 08660 Newtonian Visual Centering Device for Astrophotography (Black) A must-have accessory for centering the Moon and planetary astrophotography targets in Newtonian reflectors Low-profile design compatible with reflector telescopes and any video or astrophotography camera Small, insert able pick-off prism and built-in eyepiece lets you visually center target objects with welcome accuracy Requires just 41mm (1.61 inch) of back-focus travel Made of finely machined and anodized aluminum