This Standard specifies the dimensions necessary for the compatibility of mechanical coupling devices between light trailers or caravans and towing vehicles when the latter is fitted with a coupling ball. The clearance space around the coupling ball aims to allow coupling and decoupling of towed vehicles, and safe operation during coupling and uncoupling of mechanical devices.
ABNT NBR 16122-2012 history
2012ABNT NBR 16122-2012 Road vehicles — Coupling balls for caravans and light trailers — Dimensions