This power amplifier is compact, easy to carry, and simple to use, dual channel stereo sound, without compromising sound quality. Features: Supports BT wireless connection. Large heat dissipation area, ensure high power and high performances operation. Protections against overvoltage, undervoltage, clipping, short circuit, overheating, etc. Comapct size for easy carrying. It can be controlled through the mobilephone app, the knob and the IR remote controller(included), making the operation more convenient and quick. Aluminum alloy oxidation process, rust proof, lightweight and practical. Knob usage instructions: Rotation: Adjust the volumelevel. Click: Pause/Playing. Double click: NextSong. Three strikes: Switch playback mode (BT/AUX/USB drive). Long press: Turn on/off. Specifications: Color: black, red (optional) Material: aluminum alloy BT: 5.1 Output impedance: 4-8 Output power: 50W+50W Support voltage: 9-24Volt/ above 5A Remote battery: 1 * CR2025, 3V, 150mAh Item size: 78 * 52 * 35mm / 3.1 * 2.0 * 1.4in Item weight: 100g / 3.5ounce Package size: 150 * 90 * 70mm / 5.9 * 3.5 * 2.8in Package weight: 240g / 8.5ounce Packing List: 1 * Power Amplifier Main Board 1 * 3.5mm AUX Cable 1 * RCA to AUX Cable 1 * Remote Controller