About: http://webisa.webdatacommons.org/280881232

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 shape of the pad may be rectangular, square, round, oblong, oval or other shape so long as the top surface is flat and planar and the bottom surface 14 is generally uniformly concave and smooth from side to side.
http://www.w3.org/ns/prov#wasQuotedFrom	freshpatents.com