This is the 'Companion Chambers'. This style was used on the tripod brace that held the Chambers Lightning Rod upward. Chambers did NOT ground his system, instead he had the entire length of lightning rod run on insulators and the ends pointed upward toward the sky. How odd! This medium aqua piece is FULL of milky bands. Yeah, that is a fracture up at the top of the pinhole. Oh well, so it goes. Purchased in 2008.