Blackmagic Production 4K barrel size?

I am getting a Dtap adapter for the Blackmagic Production Camera 4K and I want to confirm the barrel size for the power connection.
Is the adapter an Outside Diameter 5.5mm cord with a 2.1mm inside diameter barrel or a 2.5mm inside diameter barrel?
Is the adapter an Outside Diameter 5.5mm cord with a 2.1mm inside diameter barrel or a 2.5mm inside diameter barrel?