<http://webisa.webdatacommons.org/438238011> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/prov#Entity> . <http://webisa.webdatacommons.org/prov/104578974> <http://www.w3.org/ns/prov#wasDerivedFrom> <http://webisa.webdatacommons.org/438238011> . <http://webisa.webdatacommons.org/438238011> <http://www.w3.org/ns/prov#value> "In some embodiments, a clamping film-holding-bar 181 includes a tube made of synthetic rubber or other elastomeric material having a hollow core 183 (which helps keep film-holding-bar 181 on film-holder opener 185 as it is slid right-to-left (in the orientation shown the drawing)) and a slit 182." . <http://webisa.webdatacommons.org/438238011> <http://www.w3.org/ns/prov#wasQuotedFrom> <google.es> .