This is a very nice, clean, heavy duty 2-1/2" capacity antique C-Clamp, marked "CINCINNATI TOOL MADE IN U.S.A. 2-1/2" IN STANDARD CLAMP NO. 540". As you can see in the pictures the clamp is in good shape, no rust, some minor pitting, very clean, not bent up, good swivel pad at the end of the screw, good pad alignment, works fine. This clamp weighs .8 pounds, and has an 5" long frame and the thickness at the clamp pad is 1.00" diameter, and the threaded screw is 1/2" diameter. A very well made 2-1/2" capacity c-clamp, by a well known tool maker!