This is a very nice, antique 10" long adjustable pipe wrench, marked "TRIMO TRIMONT MFG. CO. ROXBURY MASS. U.S.A. TRIMO SIZE 10" DROP FORGED" on the handle area, and "PAT'D 6-20-16" on the spring loaded carriage near the knurl. In good++ condition with very minimal wear, no rust, good straight metal and gears. The teeth sharpness is very good. It appears to have been a very carefully used wrench, very few dings, and those are only minor. The knurled thumbwheel design works great as it incorporates a pair of stamped steel U shaped washers, (formed to fit into the knurl wheel for smoother operation) that helps the thumb wheel turn much easier, and also protects the knurl nut and guides the moving jaw better) than those without this feature. The two knurl guides or washers are also marked "PAT'D" on them both. The washer is formed to fit into the knurl wheel, so the guides do not spin like a washer would, but remain stationary. A very nicely designed hard to find size, nice clean wrench, from the early 1920's era. Measures 9.6" long (completely closed) even though it is marked 10"on the wrench, and the jaws are .7" thick.  A very nice collectible patented wrench overall!