Code compliant Hercules RetroDrains have a one-piece spun aluminum body, heavy-duty cast aluminum strainer dome, and clamping ring for strength and durability. The Hercules RetroDrain incorporates U-Flow® Seal technology for a mechanical watertight connection to PVC or cast iron pipes to prevent water from backup damage. Available in 3-, 4-, 5- and 6-in. sizes. Hercules RetroDrains, the industry’s most popular retrofit drain, are available with a variety of options to support any project, including TPO or PVC coated flange for direct membrane attachment.