About: http://webisa.webdatacommons.org/214759255

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 nib airtight unit disclosed in these two patents uses a couple of airtight balls made of elastic and soft materials such as rubber to make up a sealing arrangement to protect the nib of a pen.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com