The JELOSTONE COmmercial Automatic Door Bottom consists of an aluminum case that houses a movable drop-bar seal. This drop-bar seal is activated by a plunger that contacts the door jamb as the door is closing. When the door begins to close, the plunger engages with the jamb, which in turn forces the drop-bar seal down against the floor or threshold. This mechanism ensures a tight seal between the door and the floor, preventing air and drafts from passing under the door. It also helps to maintain a controlled environment by keeping out dust, insects, and other unwanted elements. The smooth action of the drop-bar seal ensures that the door closes and opens quietly and without any jerks or vibrations. This type of automatic door bottom is commonly used in high-traffic areas where a tight seal and smooth operation are required, such as in clean rooms, laboratories, hospitals, and industrial facilities.