This Mitutoyo 511-201 Dial Small Bore Cylinder Gauges CG-S18A is a high-quality tool for measuring the diameter of cylinder bores. Made in Japan, it features a range of 10-18.5mm and is perfect for use in metalworking inspection and measurement. The gauge type is a bore gauge, and it is designed for use with CNC, metalworking, and manufacturing equipment. The brand is Mitutoyo, which is known for producing reliable and durable measuring tools. This particular gauge is easy to use and provides accurate measurements every time. It is a great addition to any tool kit for metalworking professionals or hobbyists.