HOLLAND couplers are coupling devices that differ from pintle hooks because the towing horn is not fixed, but pivots.
There are three types of HOLLAND couplers:
Over-the-Road
A rigid mount coupler has the coupler body fixed in location after mounting on the towing vehicle. It includes a secondary lock and is appropriate for over-the-road applications.
Industrial and Airport Ground Support Equipment
These couplers are intended for industrial material handling and airport ground support applications and are not approved for over-the-road use. They do not include a secondary lock, but feature special release systems.
Ball Hitch
A ball hitch is a ball and coupler coupling device that provides a positive, no-slack fit. These hitches allow oscillation up to 30 degrees in all directions. A ball hitch is used in applications where minimal slack is desired and a high degree of articulation or oscillation is needed