Drilljig concealed hinge with vacuum connection. In the middle fits a steel bushing (Ø10mm) with flange.

Fits on this jig wich I ordered from:

Jighole 35Mm Verborgen Scharnier Jig Kit Houtbewerking Gereedschap Geschikt Voor Gezicht Frame Kabinet Kast Scharnieren Installatie|Handgereedschapssets| - AliExpress