Matte finish. Double ring heads accurately broached & chamfered. Offset Double Ring Spanner, Sizes Between 8*10,10*12,12*14,14*17,17*19,21*23,23*24. Hardened tempered polished chrome vanadium. Spanners are constructed from a drop forged chrome vanadium steel for added strength and durability. Multiple applications: Double ring spanner for tightening or loosening screws and nuts. With clear size scale. Storage bags: The set comes with a storage bag that keeps the wrenches organized and easily accessible. This also helps to prevent loss or damage of the wrenches, and makes it convenient to transport the set from one location to another. Main business of the company:Pliers Series / Screwdriver Series / Socket Wrench Tool Set