T2 rings serve as a connector between a DSLR camera and a telescope or microscope camera adapter. This T2 ring is particularly short, which is important when connecting the camera to a telescope. It provides more space for optical accessories and allows for achieving focus, especially with visually designed Newton telescopes (e.g., Dobsons). If the camera is to be connected to a projection adapter (e.g., SLR adapter for microscopes), the T2 flange focal distance of 55 mm must be maintained. For this purpose, the CCD adapter set with various T2 extension rings is suitable.