High voltage transients caused by lightning strikes have the ability to easily destroy semiconductor junctions, and thus, cause equipment failure and loss. A lightning strike close to data lines can also cause induced ground currents that can also do serious damage. The Hyperlink AL-D8W-12 high performance lightning protector provides superior protection of RS-232, Sensors and External 12-volt data lines from these transients or surges. The low capacitance diode array assures that the RS-232 signals will not be degraded by the suppressor. This is in comparison to protectors based on high capacitance TVS diodes. The unit will protect up to eight RS-232 data lines. It will also support two RS-232 lines with no hardware handshaking or one RS-232 line with hardware handshaking. For more complete protection, two units should be used, one on each end of the line. The compact weather resistant housing features a lockable hinged cover and break-away holes are provided on the rear of the enclosure for mounting. The cable grommet may be adjusted to cable size and is removable.