N900 router AC adapter

Hi does anyone have specs for the AC adapter? I know it’s 12V/3A 36 watts, but I’m trying to find a spec for the plug, outer diameter & inner pin diameter. I need an adapter, and it’s not for sale at WD. I wonder if an adapter from a compatible product might fit.

Alternative does anyone have a source for a compatible adapter?

Thanks in advance for any help.

This information is not publicly available. Hopefully an experienced User will be able recommend an alternative.