This two section 19’ 50 watt VHF Marine Band 9dB mast mount marine antenna features phased 1/2-wave elements in a collinear array with a coaxial choking sleeve to suppress cable radiation. It is used primarily for land-based stations and on commercial vessels. Designed to communicate long-distances, the antenna is rigid enough to stay erect in rough seas, yet exceptionally lightweight. Features brass and copper elements, a chrome-plated brass bottom ferrule with an aluminum bottom sleeve for attaching to a mast. Bottom SO239 connector and two 1-3/4” U-type clamps (included). Other recommended clamp mount: 4715