Bluetooth - Built-in Bluetooth automatically reconnects to the last device. Stream your music library from your smartphone or MP3 player or use apps such as Spotify and Pandora Auxiliary - A 3.5 mm aux-in is compatible with the audio output of iPods, iPhones, smartphones, and MP3 players. Amplified - The four 4” speakers and two 1” soft dome tweeters are powered by a class A/B amplifier Weatherproof – The IPX5 rating makes sure that the weather does not interfere with your fun. USB - Charge your compatible USB devices and listen to a library of your favorite audio files Contents - 2 multi-angle adjustable mounting clamps that fits bars from 1.75” to 2”, mounting hardware, power accessory extension adaptor, multi-function wireless remote control BOSS Audio Systems provides a powerful 3-year Platinum Online Dealer Warranty so long as the purchase is made through Amazon.com. We strongly encourage professional installation of this product to ensure proper and safe functionality