The recipient of this piece, an electrical engineer, already had a shelf of mine, honoring his work with power lines. (Almost any subject is possible, at least once). A year or so later he had a surgery to reline his aorta. Being an engineer, he requested a sample of the synthetic tubing from the manufacturer. After signing a release ("I will not sell it, I will not perform open heart surgery...") he received a sample and sent it to me.
Here it is, joining rusty water pipe, passing through books on plumbing, hydraulics and the heart.

More about custom work.