... material is Oxidation aluminum alloy , this material can more effective to prevent the antenna outdoor from acid rain, alkaline and salt ... 7dBi,9.5dB,11dB,12dB,13dB,16dB. (can select) Front to back ratio:≥12dBVSWR:≤1.5Input impedance:75ΩPolarization:V/HMax ... detailsFactory ShowTest certificateMore Information and products , please feel free to contact us. Welcome to our website: www.chinabrave.com