Shakespeare Style 396-1-AIS VHF Marine AIS 4' LENGTH 3dB 4' MAST MOUNT AIS ANTENNA. The 396-1-AIS has been specially designed to meet the broader bandwidth requirements of all popular AIS transceivers. Commercial-grade construction with a mast mounting sleeve. Brass and copper elements, SO-239 connector at the base, Suggested Mount: U-Bolts included. Can be strapped to a larger mast using steel banding (not supplied), One section, Coax cable sold separately, Shakespeare Limited Warranty: 2 years. Specs: Frequency: VHF Marine Band, Bandwidth within 2.0:1 SWR: 6.0 MHz, SWR: 1.5:1 at 156.8 MHz, Gain: 3dB, Impedance (Ohms): 50, Gain: 3dB, Max. Input (Watts): 100, DC Ground: no (will read open-circuit with ohmeter test), Termination: SO-239 at bottom of antenna, Polarization: Vertical, Radiation pattern: Omni-directional.