Found this online...
This pair is for hooking up a tow "rig." It's the same type used by G.I. tankers, armored units and tow trucks to pull a disabled vehicle out of harms way. U-shaped yoke is designed to accept a hook, cable or lever. Each has a 3.8-ton (7,600-lb.) rating, is 5 x 5 1/2" and weighs a beefy 3 lbs., 12 ozs.
http://www.sportsmansguide.com/cb/cb.asp?a=198657&pn=9
Happy Hunting!
This pair is for hooking up a tow "rig." It's the same type used by G.I. tankers, armored units and tow trucks to pull a disabled vehicle out of harms way. U-shaped yoke is designed to accept a hook, cable or lever. Each has a 3.8-ton (7,600-lb.) rating, is 5 x 5 1/2" and weighs a beefy 3 lbs., 12 ozs.
http://www.sportsmansguide.com/cb/cb.asp?a=198657&pn=9
Happy Hunting!