In fact, they are not magnetic any more than they are really baluns. They are electrically identical but somewhat different in construction. No such protection is necessary if it is to be used under cover.
Connections are to three solder-pins protruding from the side of the unit.
Most of these use a wingnut or thumbscrew terminal for the antenna wire, which can be guaranteed to loosen and corrode after a while. They also use a large screw connector for the feeder such as a PL259 which, apart from being anything but waterproof, is notoriously difficult to solder. The LWC4 has an internal connector block for both the antenna wire and the feeder. The antenna enters through a grommet below the ABS case. The co-axial feeder is fully supported and sealed by a waterproof gland, also below the case.