From left->right we have: Ubiquiti AirMax 5G-19-120, Ubiquiti AirMax 5G-16-120, ARC Wireless ARC-VS5818SD1.
Then laying on the bottom we have the Laird SAH58-120-16-WB, shown without radome cover.

The Ubiquiti antennas will go on the antenna test range shortly.  Just an interesting size comparison.

--Bart