Automotive Black Bulb Type Gasket 7/32 Dia. 3/16 Backing - 20 Ft. Automotive Bulb Type Gasket used on windows and doors for large variety of vehicles such as auto vans trucks buses RV s horse/cargo trailers utility vehicles marine. Color: Black Bulb Diameter: 7/32 Backing Width: 3/16 Length: 20 Ft.