About: http://webisa.webdatacommons.org/313945032

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 an operative position, the control knob engages a collar or other member keyed to the valve stem.
http://www.w3.org/ns/prov#wasQuotedFrom	freepatentsonline.com