The 4" Cast Iron to 4" Plastic Adaptor is a high-strength coupling designed to connect legacy 4" cast iron pipework to modern 4" plastic systems (typically PVC-U or HDPE). Ideal for underground and above-ground foul and surface water applications, it provides a secure, watertight seal while accommodating material differences and ground movement. Manufactured from flexible rubber or PVC with corrosion-resistant metal banding, this adaptor ensures fast installation and long-term reliability in refurbishment, repair, or mixed-material drainage layouts.