Design allows for faster filling than conventional welded and painted systems. Stainless steel and galvanized materials of construction eliminate the need for costly painting of conventional welded styles. Perimeter construction means less area to fill with foam. No installation interference as with conventional foam dam systems. Drain slots allow for atmospheric precipitation to drains away from the rim areas. Use of “common hardware” with primary and secondary seals. Adaptable to horizontal and vertical attachment details. Less chance of wind damage than conventional designs. No Welding or flam cutting. “In service” installation.“Built –on” attachment. Ease of installation.