I bought this from McNach a few days ago for a bass where I thought the preamp was knackered. Turned out it was just a bad solder, so I don't now need this.
This is the 4-knob version, with black knobs.
It's designed for 2-pickup basses. The output of each pickup can be adjusted with two internal trim pots, ensuring perfect balance. Semiparametric mids, passive tone control, active/passive switch, bass EQ frequency window is user-adjustable (low bass 20-80Hz, high bass 40-200Hz), flat or pre-shape (slight mid scoop with boosted low/highs) options...
Check full specs here:
https://www.east-uk.com/product/uni-pre-4-knob/?v=7885444af42e
It costs new £220. Selling for £150 which is what I paid for it.
This has never been installed. I only took it out of the box to take measurements.