This is a very nice, antique combination wrench with a 9/16" hex socket at one end (set at 90 degrees to the main shaft), and a 9/16" square socket at the other end (the end with the curved bar). This wrench is 9.5" long overall. It is marked "WALDEN WORCESTER MADE IN U.S.A. PAT. PEND. 9/16 R1881" on the main bar section. The sockets are perminently attached on this model, and is about a 1/2" deep well type on both hex and square. Walden patented most of their tools between 1898 and 1920. It is rare, we never had another one like it. Outstanding quality for that period! No rust, no damage, very little wear noted!