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, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; parts and accessories thereof 90 22 APPARATUS BASED ON THE USE OF XRAYS OR OF ALPHA, BETA , GAMMA OR OTHER IONISING RADIA 90 22 21 For medical, surgical. dental or veterinary uses 90 22 21 00 For medical, surgical. dental or veterinary uses Commodity Code Description 90 22 21 00 000 For medical, surgical. dental or veterinary uses