I don't collect these but I couldn't pass it up when I saw it in a new antique mall here. These things are pretty scarce and don't turn up often. This one is close to the dimensions of #602 in the 1907 Locke Catalog. The drawing looks taller. It is a hefty 5 1/2 inches in diameter and as heavy as a brick. Instead of a bracket, these were trapped between two crossarms with a wooden or steel smooth pin down the center. In addition to dead ends, they were true strain insulators used for lines that turned sharp corners that would put too much strain on regular pintype setups. The line could pass through between the two crossarms.