Specially engineered for the extra bandwidth required by AIS transceivers, this Phase III™ antenna enables reliable communication over marine VHF frequencies. The ethafoam spacer system and silver-plated elements enhance the antenna's technical performance and longevity to meet your needs. Silver-plated outer conductor, copper inner conductorStainless steel mounting sleeveSO-239 connector inside mounting sleeve for easy mounting and dismounting for stowageSuggested mount: Shakespeare® Style 4187-HD Ratchet MountGain: 3dBBoat Length: All