This is the connector from the Carcomm powered cradle antenna coupler. It is a standard FME male connector such as those found on most RF accessories including Nokia car kits etc. The vast majority of antennas will have a plug on them that will screw into this connector.
From the photo, you can see that the connector from your antenna must have a female hole where the central pin goes, and an outer thread that then screws into the Carcomm connector.
Inside diameter of this connector is 7 mm approx
