Balun Hybrids include an impedance balun (2:1, 4:1, 6:1, 9:1, 16:1, etc) and a 1:1 balun (choke) in a single enclosure. Use on OCF, loop, terminated dipoles and similar coax fed antennas requiring an impedance transformer Suppresses common mode current on the coax outer braid (prevents your dipole from acting as a tripole!).