William Mills was the best known producer of aluminum golf club. In addition to the standard line of Mills putters, in approximately 1904 Mills released 5 additional variations of its popular putters. One of these hard to find putters was the Mills Patent CSD "Duplex" putter offered here. Similar to a Schenectady, but being a duplex club, the back of the club was the same of the clubface. A hard to find Mills putter.