Offering this nice hard to find patent adjustable screw holding screwdriver in good condition. It is marked C.A. MANN & CO. BUFFALO N.Y. PAT'D MAY 16 1889 JUNE 15 1899" on the main shaft. The jaws to hold the screw in place are spring loaded and on a slide that has a cam lock lever on it. The mechanics of the screwdriver are all in good shape, except the noted rounded corner on the driver tip. The handle is hardwood, with a steel ferrule, very solid, and minimal wear. The screwdriver is 10" long overall, and the tip is about 3/16" wide as is. The screw jaws are in great shape. A very rare screwdriver, a type I see very few of these days, particularly with the early patent dates so clearly visible!