Excel external grade telecommunication cables are made up from conductors of solid plain copper insulated with cellular (foamed) polyethylene. These conductors are twisted into pairs and the required number of pairs are laid up into units which are identified by coloured tapes. The cables are petroleum jelly filled and sheathed in black polyethylene, and are manufactured in accordance with BT type CW 1128.
The print legend on the cable now includes information regarding the DOP number, Test and Classification of the cable for traceability.