M3 cylinder stylus with 1.0 mm diameter ruby cylinder and 4.0 mm diameter x 5.0 mm long stainless steel base. Overall stylus length is 14.0 mm. Stylus weight is 0.46 gram. Cylinder styli are used for edge probing, like those found on stampings or sheet metal parts. They are not suitable for high accuracy work because their form is not as precise as a sphere. Please contact us with any questions about calibrating or using cylinder styli.