Here's a hard to find glass disc shaped insulator that I believe was used to insulate cables through walls. Embossed "ESPERANZA S.A. 121 -E.V." Measures 5.25 inches across.

Excellent condition with no chips or cracks. Light scuff marks from usage. Lots of cold mold pour straw lines on reverse. First email gets this tough insulator for only $45 plus shipping. Thanks