Adapter can be pressed into Hose inlet of Metabo ASA 30 vacuum. (Cone size: 56 mm bottom, 58 mm top, 35 mm height)
It can be printed standing without support.
About the OsVac System:
There are plenty adapters for different hoses and machines, osVAC means Universal Vacuum System.
Why osVAC (Blog side in german): https://ossso.de/osvac/
More on Thingiverse osVAC Adapter collection: https://www.thingiverse.com/hobbyhimmel/collections/osvac-adapter
The author remixed this model.