Hertz Pure Marine Certified Product stamp featuring the IP65 protection grade, ASTM-D4329 standards for UV resistance, and ASTM-B117 for salt fog operability ^^ High-efficiency tweeter designed with FEM simulation to maximize off-axis emission, typical of in-boat install ^^ Sound-transparent tone-on-tone mesh grille with twist and lock locking system, providing an elegant style and rock-solid protection ^^ Woofer with 25 mm (1) voice coil fine-tuned for infinite baffle application featuring silicone insulated lead wire for durability ^^ Sealed built-in crossover with resettable solid-state tweeter protection circuit