About: http://webisa.webdatacommons.org/122070457

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 addition, means such as a microswitch, reed relay, or other transducer is employed to sense the off-hook condition of the telephone 25, i.e. when the receiver is off the hook.
http://www.w3.org/ns/prov#wasQuotedFrom	freepatentsonline.com