Features 1、High power rejection ratio, high AM rejection, high power conversion efficiency. 2、Knob tuning, smooth feel, one button start/stop. 3、App control , it can be used to switch audio input mode/play mode/sound effect. 4、Fine sound quality. 5、Compact size for easy carrying. 6、Power reverse connection protections, short circuit protections, self recovery overheat protections. 7、Support active and passive speakers. Specification This power amplifier is compact, easy to carry, and simple to use, dual channel stereo sound, without compromising sound quality. Features: Compatible with USB disk. High power rejection ratio, high AM rejection, high power conversion efficiency. Knob tuning, smooth feel, one button start/stop. App control , it can be used to switch audio input mode/play mode/sound effect. Fine sound quality. Compact size for easy carrying. Power reverse connection protections, short circuit protections, self recovery overheat protections. Support active and passive speakers. Specifications: Main color: black BT: 5.0 Audio input mode: BT / AUX / USB-C disk / USB-C sound card Transmission distance: 15m Adaptation speaker: 30-200W 4Ω 8Ω 16Ω Output power: 20W*2 Item size: 52 * 52 * 16mm / 2.0 * 2.0 * 0.6in Package size: 83 * 76 * 40mm / 3.3 * 3.0 * 1.6in Package weight: 60g / 2.1ounce Packing List: 1 * Power Amplifier 1 * Adapter Package List 1 * Power Amplifier 1 * Adapter