This is a super professional-grade preamp that is no longer sold. It was quite an expensive piece of equipment when it was released in 2016, costing around 70,000 yen. (I think it would be priced at over 100,000 yen now) Its functions as an effects unit include a compressor, EQ, and mute switch. It also has many inputs and outputs, making it truly professional-grade. The compressor can be placed either before or after the EQ. It works quite effectively, allowing for everything from subtle compression to a heavy, noticeable effect. It has one knob, but it can be adjusted in conjunction with the GAIN. The EQ is 3-band, and each band's frequency can be selected steplessly. Perhaps due to the exquisite Q settings, the effect is quite natural. Because of this, even extreme settings shouldn't cause the overall sound to break down. The ability to turn the mute switch and EQ on and off individually or together is very useful in live performances. Level indicators are provided for input, EQ, compressor, and output. You won't understand how convenient this is until you use it, but it was a revelation. I thought it was absolutely necessary for this type of equipment. There are two inputs, and you can set the impedance and input level, which seems convenient for switching instruments (I haven't used it for switching, so I haven't benefited from this feature). The outputs include two LINE outputs, pre and post, as well as send and return. Furthermore, the power supply has a built-in transformer for enhanced performance. Rather than being designed for aggressive sound shaping, it seems to be specialized for correction. It's best used by those who prefer a direct amp sound, or by those who put it at the end of their effects chain. The manual and original box are included, but the box has some damage.