Polyplanar MA840 waterproof sub-compact box speakers. Black. Low magnetic field design. Waterproof construction. Dual cones. 80 watts per pair. 4" x 4". These subcompact box speakers are designed to fit in difficult locations and still offer high quality music sound. The ultra-low magnetic field design lets you mount them anywhere without adversely affecting navigation equipment such as compasses and autopilots. Polypropylene cones, stainless steel grills and brackets, and heavy-duty ABS enclosures make corrosion-proof and waterproof. Dual cone design with 3" main cone size.