About: http://webisa.webdatacommons.org/338474795

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 cover element has a perforated plate covered on its side facing an enclosed space such as a room, with a layer of nonwoven fiber material covering the perforations.
http://www.w3.org/ns/prov#wasQuotedFrom	patentgenius.com