TRX570 adapts patented unique suspension resonant technology with a special arc chamber in addition there is a powerful 5W super-strong speaker dual-driving power supply system and its volume is two times louder than traditional designed speaker. It is absolutely comparable with the home theather speakers TRX570 designed with classic integrated metal molding and combined with aesthetics and technology make your favorite speaker transform into an art collection. Specifications Battery Capacity - 800 mAh. Working Time - 4 Hours. Speaker - 52mm 5W. Function - Bluetooth+NFC+Microphone+Card reader. Color - Silver. Dimension - 4.1 x 4 x 4 in. Item Weight - 1.3 lbs.