Pair it, Dongle it, Speak it, Rock it! Capable of delivering high quality sound through Bluetooth transmission from a paired device, the X-mini KAI Capsule Speaker has been designed to feature a built-in Bluetooth module while keeping to the unmistakeable quality and form of the X-mini Capsule Speaker product. 40mm Drivers gives you that extra edge over 36mm drivers when it comes down to sound quality. It's not that 36mm are bad, it's just that we've made 40mm better! Bluetooth-equipped Play your favourite tunes from any Bluetooth-equipped device while you control tracks and volume wirelessly from the X-mini KAI Capsule Speaker Built-in microphone function to allow for hassle-free conference calls. Bluetooth Dongle The X-mini KAI Capsule Speaker can act as a Bluetooth dongle to the rest of your X-mini Capsule Speakers and also all other wired audio products. Rechargeable battery The built-in lithium ion battery is rechargeable via USB and offers an impressive playback time.