About: http://webisa.webdatacommons.org/337258280

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	Pyrolytic carbon is a material often used for the valve body or the occluders, although other materials such as metal, polymers or ceramics have also been proposed.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com