this tool you have here is more commonly known as a breaker bar.
yours
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new
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they come in 3/8 1/2 and 3/4 and im sure theres a 1 inch out there, but thats just not needed.
Missing the point....I know its a breaker bar, but they don't make them with the square hole in the end of the handle so you can add an extension. Try and find one.
Look closely at a flank drive open end and you'll see some grooves cut into the wrench in the opening. Those grooves etc are the "flank drive" part of the wrench.