<http://schema.org/description>
"Designed for use with various hollow-wrist robots, the QC-21HM toolchanger from ATI Industrial Automation is a QC-21 Master that enables routing air and electrical lines directly through its center."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mmsonline.com/products/toolchanger-with-internal-utility-routings>