About: http://webisa.webdatacommons.org/397344771

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	They all claim to be inaudible to humans although I can hear a sound, especially with the ones that plug into the wall and use the wiring.
http://www.w3.org/ns/prov#wasQuotedFrom	amazon.com