The 610 Series and Stormtite™ 620 Series are suitable for heavy-duty commercial applications. The 620 Series doors are similar to the 610 Series, but are furnished with weatherstripping on the exterior side of the guides, on the bottom bar and in the hood baffle. Weatherseals for the interior side of guides or hood lintel are available as options. The Stormtite door system features a steel curtain with flat-profile slats. Aluminum and stainless steel slats are optionally available.