Astral PEX-a Pro is our high-grade pressure-resistant flexible piping system with revolutionary Expansion Ring technology. This is the most advanced system for hot and cold water plumbing applications worldwide. This system comprises PEX-a pipe with Brass / PPSU (Polyphenylsulphone) fittings to ensure a durable, reliable and lasting connection. This piping system fits all installation types, be it a Single Connection, Tee Connection or Ceiling installation.