Since 1947 Dutch law has decreed that this strandbeest-yellow-tube be used to conduct electricity cables in houses. So it is very cheap. I used this tubing as early as 1979 to make a flying saucer which flew over Delft and caused a near-riot. It was four meters wide and it was lifted by helium. Sound and light came out of it. At the moment we launched it, the sky was a bit hazy. Because the saucer was black, it made a large contrast with its light background. That is why some people thought it had a halo around it. You just see a black disc without any depth. Hard to estimate the height. Police told in an television interview it was as large as the nucliar reactor in Delft (30 m). We never found it again. It disappeared in the clouds and probably landed in Belgium. A film of the UFO is on the DVD available in the webshop.