M3 cylinder stylus with 2.0 mm diameter x 7.2 mm long ruby cylinder, 1.0 mm diameter carbide stem, and 4.0 mm diameter x 5.0 mm long stainless steel base. Overall stylus length is 30.0 mm. Stylus weight is 0.69 gram. Cylinder styli are used for edge probing, like those found on stampings or sheet metal parts. They are not recommended for high accuracy work because their form is less precise than a sphere. Please contact us with any questions about calibrating or using cylinder styli.