J. Rettke, Washington MO, PAT. June 12 1962. The silver colored thumbscrew below the stem unscrews and is a 2⅜" corkscrew like device. The company is now gone having been purchased by Missouri Meerschaum. This odd looking pipe is made of briar and has a lower chamber with a metal condenser and an upper chamber that contains a filter. The smoke leaves the bowl thru the lower chamber then into the upper and out the stem. It smokes dry and cool. It has a large bowl.