I inspected my "wire" or "tube" and I see no hollow center. It simply appears to be a piece of metal wire, not sure of the metallurgic properties, but not copper.
I am at a loss. It also looks to be an aftermarket guage, as it is the only one in the pod that is aged differently.
It actually still looks really good. I cut a little more back very carefully and there is no hollow core, it is solid through and through.
