Kratt Master Key Chromatic Pitch Instrument
William Kratt "Master Key" chromatic pitch instrument. 13 keys, model A-440, patented 1931. Hinged cardboard case with instructions printed inside, measures 2.75" square x .75" thick. Round instrument has a few small rust spots on the unpainted side, otherwise in good condition. Sold as is. Inglenook Antiques...Established 1989.