class C1 tyres — tyres designed primarily for vehicles of categories M 1 , N 1 , O 1 and O 2;
class C2 tyres — tyres designed primarily for vehicles of categories M 2 , M 3 , N, O 3 and O 4 with a load capacity index in single formation ≤ 121 and the speed ategory symbol ≥ ‘N’;
class C3 tyres — tyres designed primarily for vehicles of categories M 2 , M 3 , N, O 3 and O 4 with one of the following load capacity indices:
(i) a load capacity index in single formation ≤ 121 and the speed category symbol ≤ ‘M’;
(ii) a load capacity index in single formation ≥ 122.