The SA2216 is a 2x2 2.4 GHz external antenna with 2 N-type connectors. The SA5219 is a 2x2 5 GHz antenna with 2 N-type connectors. The SA2216 and SA5219 have similar casing and form-factor.
The ENH710EXT is a dual-band 2x2:2 802.11n outdoor wireless access point with two (2) removable 2.4 GHz antennas and two (2) removable 5 GHz antennas.
Only one (1) SA2216 is needed to replace the two (2) 2.4 GHz antennas and one (1) SA5219 to replace the two (2) 5 GHz antennas.
Figure 1: ENH710EXT
Figure 2: SA5219/SA2216