This a very clean used spring inside caliper that is marked "B & S MFG. CO. PROV. R.I. U.S.A. 812", it matches the catalog No. 812-3. It measures 3" long from the center line of the pivot joint to the tips. It is in very good working order, good clean threaded rod, and solid nut, very good pivot joint, the spring is still strong. There is no rust, no pitting, no damage, light owner's markings noted on one side, and "REC" lightly etched on the other side, good tips. A quality made tool, by a well known maker!