STEREO+SUB 50+50+100 watt 2+1 amplifier for 2 echoes + subwoofer brand new unused.And the same installed in the box of the photo and tested 30 euros.Works with power supply from 8-24volt or transformer from laptop etc. Its chip is TPA3116D2.FR: 20Hz-20KHz Impedance: 4-8 ohms Input: DC 8~24V Output: 2x50W+100W 1.The power supply interface is built-in with reverse polarity protection module, and reverse connection does not damage the power supply. For high power applications, a 24V/10A power supply is recommended, and a 4 ohm loudspeaker is used as much as possible to achieve high power. 3.Each loudspeaker should be connected separately, and a strict distinction should be made between the positive and negative poles of each channel. Their reverse connection will seriously reduce the sound output performance. 4.The speaker output is BTL structure, and common grounding is strictly prohibited, otherwise the sound may exhibit anomalies and the amplifier may be damaged. If I don't answer the phone leave a message on my mobile and I will call you back