About: http://webisa.webdatacommons.org/436678208

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 convex portion 1 a is made of a material selected from the group consisting of a ceramic material including alumina and silica and a metallic material including tantalum and molybdenum that have excellent resistance to abrasion.
http://www.w3.org/ns/prov#wasQuotedFrom	google.es