M2 stylus with 2.0 mm diameter ruby cylinder, 1.0 mm diameter carbide stem, and 3.0 mm diameter by 5.0 mm long stainless steel base. Overall stylus length is 25.0 mm. Stylus weight is 0.45 gram. Cylinder styli are used for edge probing on stampings or sheet metal parts. They are not suitable for high accuracy work because the form of a cylinder is not as precise as a sphere. Please contact us with any questions about calibrating or using cylinder styli.