KEN5181320K These are called taper gauges only because of their shape. They do not measure tapers they are ideally suited for the rapid accurate checking of the inside diameters of tubing, slot widths, hole sizes, setting calipers etc. Manufactured from spring tempered stainless steel. 1mm increments.Rustless.Constant at 20°C.Satin Chrome anti glare finish.Permanent black figures and graduations.