speaker parts:Effective Height: 57.2 Overall Height: 74.5 Diameter of Mounting: 278 Outer Dia: 305.3,Center Hole:56 speaker frameFeatures: 1) Material: 0.5 to 1.0; 2) Sizes: 3 '' to 15 ''; 3) Available treatment: Zinc plating, spray chrome, painting, spray plastic, electrophoresis Speaker frame