BOSS Audio MCBK400 Weatherproof Speaker / Amplifier Sound System, Volume Control, Motorcycles/ATV and 12 Volt Applications Bluetooth Audio Streaming (Play and control music and apps like Spotify/Pandora wirelessly Through the Bluetooth Remote Control) Speakers Powered By High Performance, 2 Channel, Compact, Weatherproof Class A/B Amplifier 3.5 mm Aux-In Compatible with Audio Output of iPod / iPhone, Smartphones and MP3 Players Included: Two 3 Inch Black Speakers, One 2 Channel Amplifier, One Inline Volume Control, Adjustable Brackets Fit Handlebars from .75 to 1.25 Ideal for Motorcycles, ATV's, UTV's, Scooters, And Other 12 Volt Applications Speaker Dimensions: 4.8 x 4 x 6.1, Amplifier Dimensions: 4 x 4.5 x 4, Gift Box Weight: 4.9 3 Year Platinum Online Dealer Warranty