Sirio Antenna Tornado27 Sirio Tunable 10M & Cb Base Antenna Base station antenna omnidirectional high power handling capability whip equipped whit waterproof jointing sleeve made of aluminum alloy Type: 5/8  ground plane frequency range: tunable form 27 to 30 MHz impedance: 50 radiation (h-plane): 360 omnidirectional polarization Gain: 1.2 DBD, 3.35 DBI bandwidth @ SWR  2:  1300 kHz SWR @ res, freq.:  1.2 @ 27 MHz