This is the Tow N' Stow, Standard Tow Bar, and pressure release latch: Patent # 6,854,278B1 

This is a telescoping tow bar, so its easy to hook up. It is rated at 5,000 lbs. and has a pressure release latch developing about 14:1 leverage, so its easy to unhook.

You back up first, and then release the pressure with the exclusive high leverage release system. The patented pressure release mechanism uses a roller locking method to let you unhook easily. 
The internal rods counter rotate, so the locking dowel can slide into place while you are hitching or unhitching.

How it works: The pin supporting piece 20, "floats" on the outer square tube (first member 1). A cover 3, about 6" long, is a U shaped piece; it goes over the resilient tongue, which is a leaf spring. It also goes over the supporting piece, and makes it look good, and limits pin movement. Pry rod 22 & plate 3 pry the pin out.

The Standard tow bar is rated at 4,000 lbs. and is available in either ball or clevis tongue. 

Just pull the retaining cotter pins and dowels, and the Tow N' Stow easily extends out to the hitch (ball or clevis) on the powered vehicle.