This door seal is the original-profile rubber gasket that sits between the cab door and the door frame. It compresses when the door is closed, forming a weather-tight barrier that excludes dust, moisture, and airborne debris from the cab interior. The seal is molded to match the original door-frame contour, so it maintains consistent contact pressure around the full perimeter. Over time, the rubber loses its compliance and develops permanent set, allowing air leaks, whistling at road speed, and dust ingress around the latch area. Replacing the seal restores the original compression fit and eliminates those leaks. On installation, clean the frame channel of old adhesive and debris before pressing the new seal into place.