It allows direct coupling of any T threaded camera or accessory to Hyperion eyepieces (including MKIII Zoom) for classic eyepiece projection photography.
The Hyperion fixed focal length eyepieces or the Mark-III 8-24mm zoom eyepiece feature a male M43 thread under the rubber eyeguard. This adapter converts this 43mm thread to a male T2 thread, you then need to purchase the T-adapter for your particular camera and then attach that stack to your camera. But the MKI and MKII Baader Hyperion Zoom eyepiece uses a different SP54-T adapter.

Features: Baader M43/T-2 T-Adapter For Hyperion Eyepiece
Specification - Baader M43/T-2 T-Adapter For Hyperion Eyepiece
Kit Content:
Baader M43/T-2 T-Adapter For Hyperion Eyepiece
User Operating Instructions Manual