This is a cylinder stylus that can be used for applications where contact with ball styli cannot be guaranteed, such as sheet metal, pressed components or thin work pieces.
The stainless steel stem offers superior rigidity and is ideal for applications where weight is not an issue.
The ruby tip is very hard wearing and is ideal for most standard applications.
A silicon nitride tip is recommended if you are scanning aluminium as particles will not be deposited on the surface, unlike with ruby.
Zirconia tips are more suitable for abrasive surafces, such as cast iron parts.

Renishaw A-5000-7812 M2 ø2 mm ruby spherically ended cylinder, stainless steel stem, L 20 mm