ECEEN Wireless Speaker - Bicycle Speaker Case with Hands-Free Speakerphone Calls and Rechargeable 4,000mAh Power Bank Charge for Cell Phones, Digital Gadget Devices and MP3 Players (Red) This Speaker Has Exceptional Clarity of Sound and a Built-in Amplifier for a Surprisingly Loud Volume Connect any MP3 player or phone via the wireless or 3.5mm AUX cable, Answer phone calls using the speakers built in microphone and call answer Feature. Includes a 4,000mAh Rechargeable Power Battery Pack for up to 15 hours of continues play or charge mobile phones Sturdy case stores your Sunglasses, phone or MP3 Device and protects it from shock and weather Package contents: Portable Speaker*1Pc, micro USB cable*1Pc, 3.5mm audio cable*1Pc, instruction manual*1Pc.