Machine tools and components and numerical controls for machine tools, as follows: a. Machine tools for grinding having positioning accuracies with “all compensations available” equal to or less (better) than 15 μm according to ISO 230/2 (1988) (1) or national equivalents along any linear axis; Note: This item does not cover machine tools for grinding defined in items 2B201.b and 2B001.c. b. Components and numerical controls, specially designed for machine tools specified in 2B001, 2B201, or under a.