For sale is a Armstrong Super Heavy Duty C-Clamp. 5" Maximum opening. 3-1/4" Depth of throat. 9-1/2" X 7" Overall size (less handles and screws). Several virtually identical clamps available. All the ones I looked at were marked "Armstrong", Made in USA. These items can ship in a USPS medium flat rate box, with a small extra charge for shipping more than one.