Nixeus ARC 4.0 Ultra-Portable Bluetooth 4.0 Wireless Speaker with aptX, Internal USB Power Bank, Built in Speakerphone, Long Lasting 18 Hour Battery Life (Black) Integrated passive radiators and dual 40mm speakers for enhanced audio quality. Experience Bluetooth 4.0 wireless technology with apt for sound quality that rivals more expensive brands of speakers Enjoy up 18 hours of playback time. The ARC 4.0 charges any USB device with its internal power bank. 2 Year Manufacturer Warranty