8504.50 COILS, toroidal, having ALL of the following: (a) winding wire dia NOT exceeding 0.25 mm; (b) internal window dia NOT exceeding 40 mm; (c) external dia NOT exceeding 55 mm Op. 17.06.1985 Dec. 13.01.1986 - TC 8532473
8504.90 CORES AND SHAPES, ferrite, iron powder or molybdenum permalloy powder Op. 13.03.1984 Dec. 13.03.1984 - TC 8342777