The MFJ-901B is MFJs smallest and most affordable 200 Watt PEP Versa Tuner. Its designed to match virtually any transmitter (up to 200 Watts RF power output) to almost any antenna. This includes dipoles, inverted vees, random wires, verticals, mobile whips, beams, and others fed by coax lines or single wire from 160 through 10 Meters. It works continuously from 1.8 to 30 MHz. A 4:1 balun is built in for balanced lines. Measures 5 x 2½ x 6 inches.