About: http://webisa.webdatacommons.org/16117595

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	The rings 42 and 44 are constructed of a rigid or semi-rigid material such as titanium or plastic and then coated with a biocompatible substance such as pyrolytic carbon.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com