The Televes DAT HD is a very high gain aerial. With unique triple array design a must for poor & fringe digital areas the DAT HD also includes a built in amplifier and BOSS technology. MRD included as standard which will act as a 13dB amplifier (when powered by a 12V supply) or passive balun if no power is supplied. New asymmetrical directors to reduce echoes Newly patented dipole to improve reception margins B.O.S.S (Balanced Output Signal System) technology. The BOSS technology automatically adjusts the output signal to the correct margins. (The automatic mode is activated with a 12v supply). Don't worry about the signal strength just align the antenna and let the BOSS-Tech device automatically adjust the output signal level!