This listing is for the unit only. This unit is a version upgrade from the design of the Xotic era. It is the second generation product. It allows for 18V input, enabling a wider headroom. Basically, it gives a faithful impression of the original sound. It may not be suitable for those who actively want to shape the sound. The previous owner lost the knob tips, so some have been replaced with similar ones. It's not noticeable even when I check now, so I don't think it's a big concern. This is a used item sold privately. Please understand that there may be oversights, and purchase accordingly. Please refrain from purchasing if you are sensitive to imperfections or seek perfection. A multi-functional bass preamp, compatible with passive/active basses. - Model Name: Tri-logic Bass Preamp II - Function: True Bypass - Controls: Volume, Gain, Treble, Mid, Bass - Input Type: Passive/Active - Power: Regulated adapter, negative polarity - Output Jack: 1/4" jack Thank you for viewing.