This is a 7/16" open ended wrench on both double ended end. One end head offset at about 30 degrees, making this a special purpose wrench. Marked "BONNEY MADE IN U.S.A. 401A CHROME-VANADIUM 7/16". Made by Bonney Vise & Tool Works Philidelphia PA. A very nicely made wrench measuring 7.8" long overall.