What this Zener does in your circuit
It clamps transients at 16.9 V maximum when subjected to a 29.6 A peak pulse current (10/1000 µs waveform), absorbing up to 500 W of peak pulse power. The reverse standoff voltage is 9.1 V, meaning the diode stays non-conductive below that level, and breakdown begins at a minimum of 11.4 V.
It is a single bidirectional channel in a through-hole axial package (B, Axial), which simplifies manual assembly and rework in MRO or low-volume production.
The axial leaded package (B, Axial) is through-hole mounted, which means it fits standard 0.100-inch pitch boards and is straightforward to replace in the field with a soldering iron.