Insulator Question

[masterdan407]

I know next to nothing about insulators, but I bought this one today at a yard sale for 3 dollars because it looked different. Does anyone have any info they would like to share about it?

 

[BillinMo]

In this case, there are some markings to it gives us more info to go on than the unmarked porcelain that turns up frequently.

The PP Inc (we'd call this an "underglaze" marking) indicates the manufacturer, Porcelain Products Inc., made in Parkersburg, West Virginia. I think the date is just poorly marked and the 1 isn't visible, so this would date to 1956. The chocolate brown glaze was standard for insulators in the USA from around WW2 until the 1960s. The style would have been used for secondary electrical power distribution within residential areas.