This type of insulator was exclusively used by the Lancashire & Yorkshire Railway, and veteran collector Keith Neal never observed this pattern in use. Recently some of them surfaced on eBay, and I was lucky to win this one. Quite an odd shape with the wire grooves being quite narrow, indicating LYR did not use the thick galvanized iron wire. The two grooves indicates it was used for transposition and/or terminating of the wires. It is stamped "Bullers Ltd London" and between the grooves "LYR". Probably dates circa 1895. A nice addition to the collection!!