Rubber bottom seal that goes between the door and the floor. Keeps rain, dust, bugs, and cold air out of the garage. Sold by the foot so you buy exactly what your door width needs — no extra, no waste. Good rubber lasts because it stays flexible through hot summers and freezing winters. Vinyl and foam get brittle and crack after a season or two. If you can see daylight under the door or you're getting water inside after it rains, the seal's had it.