(1) Couplings must be classified, tested, attached and labeled by the manufacturer in accordance with SAE J684 revised July 2005.

(2) Each coupling, regardless of classification or designation, must be:

(a) Equipped with a manually operated mechanism so adapted as to prevent disengagement of the unit while in operation.

(b) Designed so that the trailer can be disconnected from the towing vehicle regardless of the angle of the trailer to the towing vehicle.

(3) Each hitch ball must be equipped and installed with a lock washer or equivalent device, and each replacement hitch ball must be marketed with a lock washer or equivalent device with instructions as to proper installation provided by the responsible manufacturer.