ach of the tubes 20 enables e g one or more sensing fibers 22 e g resembling the fibers 14 but without the strands 16 to be located within the tubes 20 for sensing a variety of non strain related properties e g temperature pressure acoustics etc in one embodiment the tubes 20 and the sensing fibers forming assemblies according to known fiber in metal tube fimt techniques by sealing one or more fibers resembling the fibers 22 within the tubes 20 according to known fimt techniques the tubes 20 may be filled with a gel or fluid to aid in the operation of the tubes 20 and or the cable 10 it is additionally noted that the tubes 20 also play a role in setting the properties and performance of the cable 10 for example by increasing the compressive strength of the cable 10 in order to avoid the cable 10 collapsing in high pressure downhole applications it is to be appreciated that ones of the tubes 20 could be replaced with solid wires resembling the central wire 18 that the central wire 18 could be hollow and resemble one of the tubes 20 or other modifications could be.