Bulb Seal
A hollow, tube-shaped vinyl seal used on frameless doors where the door meets a fixed glass panel or the wall — it compresses to close the gap.
A bulb seal has a rounded, hollow cross-section (the "bulb") on one edge and a flat mounting strip on the other. The mounting strip is usually pre-taped and presses onto the glass; the bulb then compresses against the adjoining panel or wall when the door closes, similar in function to a refrigerator door gasket.
Bulb seals are the closest thing the US market has to the magnetic profiles common on European shower doors — but they seal by compression, not magnetism. They're rated by the gap they're designed to fill (commonly around 1/8" to 7/8") and by minimum glass thickness (typically 1/4" and up).