This product includes 2.1 motherboard and knob. It adopts 6 imported disassembled three-way tube pairs, of which 4 are responsible for the channel and the other 2 are connected to the BTL circuit for subwoofer.Boot delay, instant shutdown,short circuit, overload protection. It has low noise, large output power and HIFI. Easy to install,convenient disassembly. Item 100% like the picture shown.

For parts. untested.  Sold as is.