About: http://webisa.webdatacommons.org/218846879

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 annular frame 21 is preferably made from metal, but it can be made from other material such as plastics or ceramics.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com