The Red Dolphin Audio RETROBOX Portable Mini Bluetooth Speaker is a modern take on a retro design! Along with the trusted and loved AM, FM, and shortwave modes, this speaker also has Bluetooth, which will allow you to play music from any Bluetooth device. It also can play back MP3 files from microSD Cards and USB drives. Plus, there’s a 3.5 mm aux input to hardwire other audio sources. The built-in rechargeable battery and leather strap keep the music going wherever you go.