The BA series is the cheaper version of the B series with a metal ring on the front for mechanical robustness and as all-round shielding against EMI and HF interference.
Features:
5-pole chassis connector
Less expensive version of the B-series, same size and also highest packing density
Metal ring on the front as all-round shielding against EMI and HF interference
Earth connection: Separate earth contact with the housing of the mating connector and front panel horizontal PCB mounting