"Phased 1/2-wave elements in a collinear array with a broadband matching section, and a coaxial choking sleeve. Designed to get the message through when all others fail. Its unique design puts the signal on the horizon, providing gain in all directions. For heavy duty seagoing applications, such as workboats, tugs, etc. An excellent choice for land based stations. Brass and copper internal elements. SO-239 connector at the base. One section. Mount: the 476 has a 2-3/4" diameter x 26" long 6061-T-6 aluminum sleeve which can be strapped directly to a mast or used with Shakespeare style 483 clamp set or style 484 wall mounting brackets."