The original Fender System I base was die cast from metal so soft that 3 steel plates had to be added under the base at the factory to prevent the string from gouging the soft metal when clamped. Our new single piece base looks identical, is more durable, does not need extra plates and resonates all day long due to the high density of 7075. It also has the correct hole pattern and 8 inch bottom radius to mount flush to the curved area of the head stock. Comes with 4 mounting screws and a 3.0mm Allen key. Guaranteed to fit or your money back! Fits: Schaller 1985-1987 Fender Contemporary Stratocasters with the System I and II tremolos or 1988-89 MIJ/USA models with the Kahler 2520 traditional tremolo.