ZSI H-7056B-AL, Beta Heavy 3" Pipe Stacking Kit Aluminum. Recommended systems with greater than 1500 PSI operating pressure, operations with pressure surges, and applications with wide temperature fluctuations. Absorbs high levels of shock, noise, and vibration. Cushions are polypropylene (Green color) or Aluminum. Aluminum cushions and are used in higher heat applications up to 500 Degrees.