Ermetic drain connectors for connecting roof membranes with drains. Tapered tang and knurling for perfect coupling. Guaranteed long-term watertightness, compatible with EPDM synthetic sheets. Ermetic drain connectors are used to connect roof membranes with rainwater drains. The slightly conical-shaped tang facilitates installation in rainwater pipes. The elastic material from which they are produced guarantees a long-lasting seal. Knurling at the top of the tang ensures a perfect attachment of the Leaf-Excluders and Gravel-Excluder to the drain connector.