I see sellers saying this is 1940s. According to the model number it was 9/32 drive, but it has been modified/ground down. I was able to make it register on the dial, but I have not compared it to a freshly calibrated wrench, and it feels somewhat sloppy. Ground shipping could take 3+ weeks. Please choose flat rate priority if you need it quicker, and flat rate could be a little cheaper to the East Coast.