Model Description MHz Gain MaxWind 1487 5' 7" Tall Single Section with 5/8 Wave 3 Elements Radial Lingth 20 1/2" 134 – 184 4.5 dB 135 MPH Tram Fiber Glass Base Antenna: High performance, 200 watts power rating low SWR and broader band. In models with multiple sections there is a special design of the joint bracket to connect fiberglass tubing that enables the antenna to maintain the same strength as one. The radiator and coil are hermetically sealed in fiberglass tubing to assure low SWR in all weather. DC Ground construction allows static dissipation for low noise ratio and maximum lightning protection. Vertical polarization with 50 ohms impedance. Mast diameter accepted is 1 3/16" to 2 7/16" – UHF Connector. Click Here for antenna trimming chart.