Ubiquiti AG-HP-2G20 Quick Start Manual page 9

9. The Release Button indicates the Antenna Feed polarization.
Confirm that the polarization indicator, V or H, on the
Antenna Feed matches the indicator on the Grid Reflector.
WARNING:
Vertical Polarization
10. Re-attach the cable feed door to the Rear Housing. Ensure
the locking tab securely latches to the Rear Housing.
The polarization indicators must match.
Horizontal Polarization