ZoeeTree S4 Wireless Bluetooth Speaker, Portable Stereo Subwoofer with HD Sound and Bass, Built-in Mic, Bluetooth 4.2, TF Card Slot, Outdoor Speakers for iPhone, iPad, Samsung etc (Green)Excellent Stereo Sound: Advanced patent amplifier IC boost maximum volume enhance up to 50%. 5 x 2 watts high end low impedance speakers larger than normal 10 watts. The higher and deeper voices are crystal clear without any noticeable distortion, even the volume turn up. Bluetooth 4. 2 Technology: Quick to Connect the devices in seconds. It also can be used as a hand free Speaker Phone or to notify you of incoming messages with built in Micphone.