About: http://webisa.webdatacommons.org/205058158

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	Many ofthe prior art devices are attached to roof by a screw, nail, or other fastener which pierces the roofing surface.
http://www.w3.org/ns/prov#wasQuotedFrom	patentgenius.com