The C820A Outer Corner moulding has been designed to compliment our largest exterior cornice moulding, the C820, eliminating the need to mitre 90 degree corners. A 90° Inner Corner is also available. C820A Outer corner cornice. Suitable for larger decorative external cornice work. The term cornice comes from Italian cornice, meaning ledge. Cornice molding is generally a horizontal decorative molding which crowns any building. The function of the projecting cornice is to throw rainwater free of the building's walls. In residential building practice, this function is handled by projecting gable ends, roof eaves, and gutters. Install using the correct adhesives. To Fit: C 820 Exterior Cornice Made from Light weight resilient polyurethane.