Zenor Diode Needed for Pixhawk?

I see that a zener diode is recommended when powering the Pixhawk on the rail (as a secondary). I am using 4in1 ESC. I dont see any zener diodes for sale on unmannedtech. Any thought on this?

Thanks

Hi

Is there any reason why you are not powering your Pixhawk via the power module as that is by far the best way to power it as it also gives the ability to provide battery information to your Pixhawk autopilot.

There may be a few cases when you need to power pixhawk via ESC, but generally its best to power via the power module