This page shows the pintypes and a mine insulator (U-94).I've never seen just a Square D Co. marked mine but have the U-94 Okio Brass Co. And Elreco marked pieces but they do not have the Square D logo on the bottom. Several things caught my eye on this page. It does not list the U-317 in white or brown color. It showes the U-32 which you always find in cobalt blue but it also lists one in brown! Another interesting thing is it is called a Police Pin Insulator. Could that be the reason these are found so comonly in blue. were they intended for alarm system lines. The mystery thickens. I was surprised to see no pictures of the Ohio Brass U-97 or the U-280B listed. Perhaps in a later or earlier catalog since this is eight years from when they started making porcelain insulators.