This is a good used 15" long adjustable wrench marked "DIAMOND TOOL AND HORSESHOE CO. DULUTH MINN 15IN" and FORGED DIAMALLOY STEEL MADE IN U.S.A." in raised cast lettering. The jaws are in great shape with a clean plain finish, only minor edge and corner dings noted, no rust.  We note a past owner's 4 letter stamp on one size. The jaws are 1/2" thick at the narrowest point, and adjust smoothly. A nice clean vintage wrench from the mid-1900's!