The HF-SSB Automatic Antenna Tuner Unit (ATU) model F2265E is an antenna matching network that provides efficient RF power transfer from the radio system to the antenna. The ATU handles up to 125 watts Peak Envelope Power (PEP).  F2265E matches the antenna impedance to the 50Ω output impedance of the radio system, with a nominal VSWR of 1.5 in the 1.6 to 30 MHz frequency range.