Without a maker's mark, but surely Brown & Sharpe-made, this is a distinctive and very desirable straight edge. It is in an odd size 22 ½ inch length, with a 1 5/16” width and a thickness of 5/16”. Its most distinctive feature is a slightly offset finger groove (on both sides) that is well japanned. It is the nicest looking straight edge that I've seen. The B & S origin can be seen by looking at the vertical upright on the B&S No. 585 Vernier height caliper (MA6) which is of the same dimensions, but unstamped or grauduated. Fine.