Bowers & Wilkins Marine 6, 2-Way Ceiling Speaker System, 1x 25 mm Soft dome tweeter, 1x 150 mm Polypropylene diaphragm midrange woofer, Frequency range: 55 - 30,000 Hz, Peak SPL: 89 dB, Impedance: 8 Ohm, Recommended amplifier power: 20-80 W, Frame diameter: 243 mm, Diameter of the installation opening: 202 mm, Depth (behind the surface): 82 mm, Distance to the surface: 8 mm, Colour: Black, White grille included