Section 18 OPTICAL, PHOTOGRAPHIC, CINEMATOGRAPHIC, MEASURING, CHECKING, PRECISION, MEDICAL OR SURGICAL INSTRUMENTS AND APPARATUS; CLOCKS AND WATCHES; MUSICAL INSTRUMENTS; PARTS AND ACCESSORIES THEREOF 90 OPTICAL, PHOTOGRAGHIC, CINEMATOGRAPHIC, MEASURING, CHECKING, PRECISION, MEDICAL OR SURGICAL INSTRUMENTS AND APPARATUS; CLOCKS AND WATCHES; MUSICAL INSTRUMENTS; PARTS AND ACCESSORIES THEREOF 90 17 SPECIFIED OR INCLUDED ELSEHWERE IN THIS CHAPTER. 90 17 20 OTHER DRAWING, MARKING-OUT OR MATHEMATICAL CALCULATING INTRUMENTS Commodity Code Description 90 17 20 00 OTHER DRAWING, MARKING-OUT OR MATHEMATICAL CALCULATING INTRUMENTS