Take my word for it, you don't want a high desity weaterstripping for a door - it won't adapt to the varying gaps to be filled, and you probably won' be able to latch the door. The 1/4" by 1/2" size fits most OLDER exterior doors. On the top and lock side of the door, mount the weatherstripping on the edge of the door stop, but on the hinge side, mount it on the face of the jamb just inside the door stop. If you mount it on the stop by the hinges, closing the door will pull it off. Been using this type for 50 years. Oh, Amazon shows this product as a HIGH density, but it (product #02071) actually IS the low density that that you want. If you have a newer door unit that has a weatherstripping that looks more like auto door weatherstripping, you have to pull off a section so you can find and replace it with similar product. These generally have a spline that inserts ito a slot.