Baader's new Mark III zoom eyepiece features a 43mm thread under the eyeguard for attachment of various imaging adapters. This new camera adapter from Baader can be attached to the male M43 thread on this eyepiece on one side. On the other side, this adapter has an M54 male thread and can be connected to Baader's various HDT rings. These HDT rings are available for a wide variety of camera thread sizes. So by using this adapter plus the appropriate HDT54/xx adapter for your camera, you can connect your camera to Baader's Mark III zoom eyepiece.
To attach the Baader Mark III zoom to a standard T thread, use the HTA43/T-2 adapter instead. This adapter cannot be used with the older Mark II zoom eyepiece.