The adapter is screwed onto a male T2-thread and allows for attaching SC accessories like correctors or adapters. It is a good connection adapter if you want to connect your Schmidt-Cassegrain accessories to other systems via T2.
Female thread: T2 (M42x0.75) threadMale thread: SC / 2″ Schmidt-Cassegrain threadOptical path: only 1 mm (the SC thread is completely sunken into the connection adapter)Length of the SC thread: 5.5 mm