CISCO (AIR-ANT2524DW-R) 2.4 GHZ 2 DBI/5 GHZ 4 DBI DIPOLE ANT. WHITE RP-TNC, Wireless Data Network, Dipole Form Factor, 4 dBi Antenna Gain The next generation of Cisco Aironet 802.11n access points -the Cisco Aironet 3600e Series and 1550 Series- requires the use of dual-band external antennas to make them fully functioning units