| http://www.w3.org/ns/prov#value | - Conventionally, the tubes 3 of units 5 containing optical fibers 2 are made of a material that is hard and rigid, such as high density polyethylene (HDPE) or polybutylene terephthalate (PBT); they may also be made of a pair of layers comprising polybutylene terephthalate and polycarbonate (PBT/PC).
|
