Spanner is designed with two different sizes on each end. The 18mm end is suitable for 18mm nuts and bolts, while the 10x11mm end is designed for nuts and bolts with those dimensions., Taparia is known for producing high-quality tools, and the 18-10X11 Ring Spanner is no exception., Taparia 18-10X11 Ring Spanner is a versatile tool suitable for various applications. It can be used in automotive repairs, mechanical engineering, construction, and other tasks.