The starter that I installed from the auto parts store was non-vented, and nearly matched the original one installed in 1973. Perhaps I was too simplistic in my explanation, and I certainly do not want someone else to create an unsafe condition. These same Universal built motors were also used in a lot of land uses, primarily construction equipment where they were non-vented because of dust and dirt. Suitability for marine use, and somewhat enclosed compartments, is worth looking into, and I apologize for not mentioning that. Prstolite sure sounds automotive.