Section 18 Optical, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; clocks and watches; musical instruments; parts and accessories thereof 92 Musical instruments; parts and accessories of such articles 92 09 Parts and accessories for musical instruments; metronomes, etc 92 09 91 Strung backs, keyboards and metal frames for upright pianos 92 09 91 10 Strung backs, keyboards and metal frames for upright pianos Commodity Code Description 92 09 91 10 00 Strung backs, keyboards and metal frames for upright pianos