This coupler latches when the trailer is lowered onto the ball. It also has a molded hitching guide to make coupling easier. To uncouple, you simply pull a release cable located near the trailer jack handle. The GN8 coupler has a "V-19" rating of 28,000 pounds.
These units are fabricated using extra heavy wall tubing for maximum strength. They are rated at 24,000 pounds gross trailer weight.