The Integra Drain system seamlessly welds the drain to the sink. This creates an integral drain in-sink system, without any additional parts or rings resulting in a seamless drain interior. This provides a cleaner look, which is also more hygienic. The visible drain flange has been eliminated, so the interior has no CRACKS or CREVICES inside the drain, which eliminates standing water when not in use.Integra Drain-Residential-Single Bowl