Same as Polychorus. Kurt had two of them apparently, and used them on the Unplugged show. However, I don't know what songs he used it on. I don't think he used it one any songs, but Guitar World says that he was arguing with MTV techs over the various qualities of the Echoflangers.
THE FORGOTTEN MARINES OF TARAWA. During late-November 1943 one of the most savage battles in the history of the Marine Corps took place on the tiny island of Betio, located in Tarawa Atoll. The capture of this island took three days and cost the lives of 990 Marines and Navy Corpsmen. In addition to these, another 2,200 were wounded.
The Washing of the Spears: A History of the Rise of the Zulu Nation Under Shaka and Its Fall in the Zulu War of 1879. Da Capo Press. ISBN 978-0-306-80866-1. Raugh, Harold E. (2011). Anglo-Zulu War, 1879: A Selected Bibliography. Scarecrow. ISBN 978-0-8108-7227-1. Spiers, Edward M. (2006). The Scottish Soldier and Empire, 1854â1902.