The OMG Hercules Aluminum RetroDrains (SKUs HDAL3A, HDAL4A, HDAL5A, HDAL6A) are durable retrofit roof drains designed to replace existing drains in re-roofing projects without removing the existing drain fixture. Each drain features a one-piece spun aluminum body, heavy cast aluminum strainer dome, large flange for secure membrane attachment, and a U-Flow mechanical watertight seal that connects reliably to existing plumbing (PVC or cast iron). These drains meet multiple codes and standards...