[Boatanchors] Western Electric Varistor: What and Where Used?

[William]

Hello All,
Today's question for the crowd is:  What is a Western Electric 46C Varistor?  This was included in a miscellaneous box from an estate sale and I did not want to throw it away since it was still in its original packaging.
For extra kudos, feel free to provide any other details/links/references as to its purpose and where it was used.  I could not find anything in a web search.  Perhaps there is a Web Wizard out there.
Thank you in advance!
Best Regards,
Willliam