About: http://webisa.webdatacommons.org/268741264

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	In another embodiment, such as described in FIG. 18C above, where two proximity heads 1710A and 1710B are utilized, the shaft 2016 could also be hollow and allow for a third concentric shaft to pass through.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com