The Allanson RSS 496 Ballast is a direct replacement for ferromagnetic ballasts, which requires no rewiring. This ballast has a smaller profile that allows for greater adaptability for low profile signage and is for use with T8a and T12 HO lamps (2' to 10' in length). Using the RSS 496 Ballast can also increase lamp life and has quiet operation in all installation conditions, with a sound rate of "A".