Polk Audio DB351 3.5-Inch Coaxial Speakers (Pair, Black) Pair of marine certified speakers perfect for use in boats of all types Equipped with 0.5-inch liquid-cooled silk-polymer composite dome tweeter and a neodymium magnet Maximum input power: 105 watts 3.5-inch diameter size is perfect for unobtrusive installations Durable butyl rubber surround stands up to the stress of extreme temperatures, sunlight and time