Hello @mystery,
As per our previous reply at Exterior antennas and Amplification BR1 - #8 by mldowling, use a solution that supports the MIMO connections of the device if you want to use the full benefit of what it can deliver.
There is a detailed Antenna Selection Guide that has been made available to all Peplink Partners that supersedes the information previously mentioned in this thread, please ask you local Peplink Partner for a PDF copy.
Happy to Help,
Marcus 