Smoother action positive seal mechanism.
The drop-bar seal is actuated by a plunger which contacts the jamb as the door is closing, forcing the drop-bar seal down against the floor / threshold. Pemko Door Bottom W/ Pemkoprene Insert 36"L x 1-5/16"W Mill Aluminum.All pemko automatic door bottoms consist of an aluminum case which surrounds a movable drop-bar seal.