G-Project G-ZIP Ultra Portable Line-In Wired Multimedia Speaker with Rechargeable Battery (3.5mm AUX) Universal compatibility with all devices with 3.5mm headphone jack. Rechargeable Battery - Built in rechargeable lithium-ion battery lasts up to 8 hours and charges through USB port. Retractable Cable - Never lose the cable, there when you need it and hidden away when you don't.