Dual Bluetooth lets you connect two smartphones simultaneously. NFC technology lets you pair your Bluetooth phone instantly, just by tapping it on the receiver's volume knob. Voice control with Siri eyes free and song pal. Output power (4 ohms, 1 kHz, 16 Volt): 55 Watt High-power amplifier delivers clear, natural-sounding audio UV-resistant finish and anti-corrosive coating for durability Aoa 2. 0-Compatible USB port lets you connect music players and smartphones