I'm looking for some very thin tubing. I need something a less than 1/8" OD. I need it to be about 8" long and rigid. It doesn't have to be metal, but it does need to be reasonably durable. Any ideas what I might be able find? Where I might find it?

I'm making a probe extention for one side of the sampling tube for a Shortridge digital pressure differntial gauge. The probe will be passed through perforated floor tiles in a data center. I need to take pressure differential measurements between above and below floor.

I could go to Lowes or HD and poke around, but if anyone knows of something specific I could look for, that might speed my search.

Thanks,

an aluminum rod?

Carbon Fiber arrowshaft

How large is the smallest size of brake (hard) line? Probably just a bit too big, but that was my first thought.

capillary tubing: http://www.mcmaster.com/#catalog/116/128/=5lid5m

Thanks Alan, that looks like exactly what I need.