ASUS SP-BT23, 2.0 channels, 4 W, 4 Ω, 70 dB, 150 - 20000 Hz, White ASUS SP-BT23. Audio output channels: 2.0 channels, RMS rated power: 4 W, Impedance: 4 Ω. Product color: White, Driver unit: 0.0984" (2.5 mm). Battery type: AA, Battery voltage: 5 V, AC input voltage: 100 - 240 V. Battery technology: Alkaline. Weight: 14.1 oz (400 g)