<http://schema.org/description>
"A ballbar testing system has three main components: the ballbar, a precision magnetic mount that attaches to the machine table, and a second precision magnetic mount that attaches to the machine spindle or spindle housing."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mmsonline.com/articles/ballbar-basicsrunning-around-in-circles>