All the categories for interchangeable towed equipment are shown below. ‘Interchangeable towed equipment’ means any vehicle used in agriculture or forestry which is designed to be towed by a tractor, changes or adds to its functions, permanently incorporates an implement or is designed to process materials, which may include a load platform designed and constructed to receive any tools and appliances needed for those purposes and to store temporarily any materials produced or needed during work and where the ratio of the technically permissible maximum laden mass to the unladen mass of that vehicle is less than 3.0.
Category S
Interchangeable towed equipment.
Each category of interchangeable towed equipment is supplemented at the end by an ‘a’ or ‘b’ index, according to its design speed:
a) ‘a’ for interchangeable towed equipment with a maximum design speed below or equal to 40 km/h;
b) ‘b’ for interchangeable towed equipment with a maximum design speed above 40 km/h.
Category S1
Interchangeable towed equipment where the sum of the technically permissible masses per axle does not exceed 3 500 kg;
Category S2
Interchangeable towed equipment where the sum of the technically permissible masses per axle exceeds 3 500 kg.