The new Hy-Gain P 500 antenna

[bluemagoo]

Back in the 70s I had this antenna tuned for the 10 meter band. Hy-Gain has reintroduced this classic but I cannot locate specific details about the construction. What is 'ply-tubular' ? The old 'Super Penetrator' was constructed using only aluminum. What materials were used in the construction of the newer model?

link: Hy-Gain

Thanks.