Viigoo are the Only Authorized Amazon Resellers for Viigoo Brand Products. PLEASE do not purchase from other sellers other than Viigoo or your purchase to be protected by our warranty. Feature: Resonance technology of low frequence 360-degree omni-direction sound field 360-degree rotary volume control technology Speaker Specification: Item name: Mini speaker Lithium battery : 3.7V 500mAh Recharging voltage: 5V Horn specification : 40mm 2.6Ohm 3W Frequence response : 60Hz-18KHz SNR(Signal to Noise Ratio) :¡Ý95dB Distortion degree : ¡Ü0.5% Measurement: 60*60*53mm Packing list: 1 x Speaker 1 x Two-way Cable(one is USB for charging,the other is AUX cable) 1 x User Manual