Wireless Bluetooth connection, built-in bass port and Li-ion rechargeable battery, thatâ€™s JBL Flip Portable Stereo Speaker for you in a nutshell. It is the perfect wireless stereo system for your smartphone and tablet. With two 1-5/8-inch drivers and a built-in bass port, it delivers full-range sound with exceptional bass. It offers up to 5 hours of playback time, thanks to its built-in Li-ion rechargeable battery. This ultimate wireless portable stereo speaker connects wirelessly to any Bluetooth-equipped device. It can play from either a vertical or horizontal position, so you can place it in any position and location to enjoy unperturbed music. It also fits easily into a backpack, so carrying it anywhere becomes easy.