About: http://webisa.webdatacommons.org/255376347

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	Weight is an important advantage; according to one manufacturer a C39 lens is up to 50 percent lighter than a comparable glass lens ?? more comfortable for divers requiring thick lenses.
http://www.w3.org/ns/prov#wasQuotedFrom	dtmag.com