About: http://webisa.webdatacommons.org/456537755

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	In the embodiment shown in FIGS. 1A and 1B, diaphragms 23 and 28 are very thin, preferably less than one (1) mm, and can be made from any suitable material, such as aluminum, steel, or plastic.
http://www.w3.org/ns/prov#wasQuotedFrom	patents.com