Compatible with CB radios from many brand , improve quality and range to CB radio reception. The antenna works on all channel within CB radio frequency range of 26MHz to 28 MHz（Center 27MHz）, No tuning needed； Frequency Range: 26-28MHz (Center Frequency: 27MHz)；V.S.W.R: 1.2:1；Impedance: 50 Ohm；Antenna Height: 23cm(9inch)-130cm(51inch) full extended; Compatible with：Any 27Mhz Antenna working for Hand Held CB radios Cobra, Midland, Macon, and Radio Shack with BNC Connector; This is one of the best choices when you need a simple and lightweight replacement antenna that is easy to install; Don't worry about any problems, we have carefully checked each product, Any questions, please feel free to contact us, will reply within 24 hours; Compatible with CB radios from many brand , improve quality and range to CB radio reception. The antenna works on all channel within CB radio frequency range of 26MHz to 28 MHz（Center 27MHz）, No tuning needed；