The Wavin Osma Squareline Drain Adaptor Square to Round 61mm Black (4T836B) is a high-quality PVC‑U rainwater fitting designed to connect Squareline 61mm gutters to round drainage pipes. Ideal for domestic and commercial installations, this adaptor ensures a secure, leak-free transition from square to round pipework, supporting efficient water flow and reliable drainage. The black finish blends seamlessly with external gutters and downpipes, offering a neat, professional appearance and long-lasting performance within Wavin Osma Squareline systems.