Check the listing for details. Poly-planar MP3 Adapter Waterproof Marine Audio Systems. Condition: New. Listed at 10.00 USD. New - Out of Box This Poly-planar MP3 Adapter is a high-quality product designed for use in marine audio systems. It is specially crafted to provide superior sound quality and is waterproof, making it ideal for use in boats and other marine vessels. The adapter is compatible with a range of devices and is easy to install, ensuring that you can enjoy your favorite tunes without any hassle. The adapter is manufactured by POLY-PLANAR, a trusted brand in the industry, and comes with a manufacturer part number of IC-3.5PM MP3. It is a must-have accessory for anyone who wants to enjoy music while out on the water. So, if you're looking for a reliable and high-quality MP3 adapter for your marine audio system, look no further than this Poly-planar product.