Push Button Quick Detach Socket with Rounded Eyelet (v6) - Metal Version
Strong rounded eyelet for ring connectors and round barrel body for use with push button swivels.
When printed with one of the strong and flexible plastics, the inner clearance is 9.55mm in diameter. So it will fit a 9.5mm diameter barrel push button swivel quick detach. Typically, these are the ones that support the 1.25" nylon webbing belts.
Note, different push button swivels might have different diameters for the shaft. Be sure your push button quick detach swivel's shaft is 9.4-9.5mm in diameter range before ordering.