About: http://webisa.webdatacommons.org/380427708

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	Each of the sealing discs 41 includes an annular metal ring 42 (FIG. 4) having a low friction coating 43 bonded to one surface, and having a layer of elastomeric material 47, such as rubber, bonded to the other surface of the ring 42.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com