TUNZ delivers incredible sound from such a small space because we use two x 3-watt drivers and a Passive Radiator for superior base quality. TUNZ also performs as charger. The extra large battery, for extended playtime, also performs as a charger for smartphones or tablets. The built-in Noise Cancelling Mic allows you to seamlessly switch from music to hands free calling. Each TUNZ Portable Bluetooth Speaker comes with 3 interchangeable surface vibration absorbing silicone bands, which cancel surface-to-speaker rattle, so you can choose you're color and change it up to either red, blue or black.