This set includes combination style spanners that have the versatility to use an open end or a ring end. All of these spanners are now thinner and lighter than both older models (and a lot of their competition), which reduces hand fatigue without compromising on durability. The full range of ToolPRO spanners are made from ultra-durable chrome-vanadium steel, and finished with a bright, mirror-like polish, making them practically immune from corrosion, and quite nice to look at. ToolPRO Spanners meet and exceed both DIN and ANSI standards, so you can be sure that they are sturdy enough to tackle any job you need done.