GoldMaster Mobile-20. System type: single speaker, Recommended usage: universal, Speaker placement: Portable. RMS rated power: 2.8 W, Frequency range: 100 - 20000 Hz, Signal-to-Noise Ratio (SNR): 85 dB. Connectivity technology: Wired, Speaker interface type: USB. Width: 50 mm, Depth: 50 mm, Height: 35 mm. Battery voltage: 3.7 V, Battery life (max): 6 h