. High quality extruded aluminium strength and optimum corrosion protection.. The Radiator being "U" style is specially design to give a superior performance over the UHF-Band : 470-770 MHz.. The core-less transformer, is built in the Feeding Unit and make it easy to connect with either coaxial cable (75 ohms).Lightweight but robust construction .. Simple Assembly.. Compact neat and unobtrusive design.. HDU-25 are provided with support brace for, higher stability mounting.