About: http://webisa.webdatacommons.org/8133087

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 balls 2 are preferably made of ceramics, such as alumina, silicon carbide or zirconia, being superior in resistance against thrombus and friction, or made of metal, such as a titanium alloy or a cobalt-chrome alloy.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com