The AL-D4-05W is a high performance 3-stage weatherproof protector that provides superior protection of differential or balanced digital or analog lines from transients and surges. This unit will protect up to four pairs of lines or eight single ended data, analog or control lines.The AL-D4-05W series is designed to convert into a failsafe mode in the rare case of a catastrophic surge or lightning event. For this mode, the resistors in the second stage will fuse and portions of the diode array will short. This effectively disconnects the line from sensitive equipment thus limiting damage. The units are factory repairable.These protectors feature a weatherproof ABS enclosure with gasketed cover and concealed mounting holes. Removable screw terminal strips are provided on the input and output for convenience. To ease installation, the terminal strips can be removed. A ground clamp provides a tie point for earth ground.Application Note: Not for use with T1 lines with Ring or DC Power.For mounting to masts up to 2 inches in diameter, the HGX-PMT25 mast mounting kit is available (sold separately).For additional information and complete specifications, see data sheet below.