This International Standard lays down the dimensions necessary for the compatibility of mechanical coupling devices between light trailers or caravans and towing vechicles when the latter are fitted with a coupling ball. The clearance space around the coupling ball is intended to allow coupling and decoupling of towed vehicles, and safe operation during coupling and uncoupling of mechanical devices.
This International Standard aplies to coupling balls designed for caravans and light trailers of categories O1 and O2, which have a maximum authorized total mass (ISO-M08), as defined in ISO 1176, less than or equal to 3,5 t. It does not necessarily apply to special trailers drawn by special vehicles.