The CONNEX Air unit antennas are lightweight 2dbi cable antennas with a MMCX connector.

CONNEX was tested with those antennas and can reach 1000 meters in line-of-sight conditions, still there is an option to replace the antennas with different antennas with similar MMCX connectors. The advantages and limitations of other antennas are described in Can I Increase Range with Specialized Antennas?

The dimensions of the MMCX connectors used on the CONNEX Air unit can be seen in this drawing: