This is a spool type insulator with the pinhole through the middle. It has very straight sides when compared to other CD 187s I've seen, and a ridge inside. You might be able to see the ridge if you look toward the right side of the picture on the top right. The only embossing is a vertical bar. I didn't know of a variation in shape, so I contacted N.R. Woodward about it. He was kind enough to reply with this information: "The no-name insulator you have is a Brown pony, it fit the bottom end of the special Brown pin that provides for a regular insulator above the crossarm, and the Brown thru-pin hole insulator on the bottom end, below the crossarm. Your specimen has a somewhat different configuration from the ones made by Brookfield (embossed PAT'D NOV 23D 1886) but I think not sufficient to merit a different CD number. The Brown Pony is CD 187, CD 188 is the Brown Deep Groove, same style but much larger."

If you have additional information, let me know.

Thanks & good collecting, Sandia - www.insulatorstore.com