The sspeaker is very loud, even at the highest volume is not distorted, high quality Built-in microphone for HD hands-free calling^ Portable speakers are compatible with most audio/video devices such as smartphones, computers, PCs, iPads, etc.^ Bluetooth phone speakers are equipped with advanced Bluetooth technology and are compatible with all Bluetooth devices. ^ The phone can display the remaining power of the speaker, connecting the device in just 3 seconds, connecting up to 30 feet (10 meters)^ Portable phone speaker weighs size: 9x3.2x2.3 inches. Built-in 2000 mAh high-capacity rechargeable lithium battery, very suitable for outdoor and indoor use, easy to put into the backpack or suitcase