This style of porcelain was manufactured by the Pittsburg High Voltage Insulator Co. of Derry, PA. The company was founded in 1908. Pittsburg produced these for the Postal Telegraph Company. This is a nicely marked one, as well as having the added features of a strong mold line over dome, and two "dents" in the dome which occured before the initial firing. The color is a medium brown with some darker tones here and there. There is some rubbing in the wire grooves from the original iron wire, and a very small chip in the wire groove on the back. No major chips or cracks. Asking $35.00 plus postage. Sorry about the pic. Best viewed laying on the couch:)