Unleash the full potential of your full-frame DSLR on large EdgeHD optical tubes with the Celestron 48mm T-Adapter. Designed to replace the smaller standard 42mm adapters, the larger diameter provides a larger light path to the camera to maximize the available amount of light while reducing or eliminating vignetting around the corners of the sensors, which can occur when using the smaller adapter with full-frame sensor cameras. This larger adapter is ideal for 9.25", 11" and 4" EdgeHD OTAs, and requires the use of an optional 48mm camera-specific T-ring to work correctly. It will not offer any advantage to cameras and imagers with smaller APS-C sensors.