This is the EVA dual effect pedal. See the demo videos for some suggested settings and available sounds.
This dual effect box is the EVA Fuzz, a pedal aimed at guitarists that want a fuzz pedal with a full response - not scooped like a muff or too uncontrollable, like a Fuzz Face (or derivative). It's based on the Fuzz Factory and sound of the Black Russian Big Muff, as well as the preamp section of the Roland Space Echo. If you're the sole guitarist in a band (as I am), you need a big and articulate fuzz that's interesting tonally, but controllable and not too crazy.
When recording, I usually run my fuzzes into an original RE-101 Space Echo (the tape echo), so the left switch is a boost based on tracings people have done of the preamp of that unit. It has quite a massive boost on offer so use carefully if you don't want to blow out a speaker!
It's a hybrid silicon/germanium fuzz, with four controls in total. The first two alter transistor bias (think of one as a gate, and one as a way of changing the 'character' of the fuzz - silicon to the left, germanium to the right); the other two are a fuzz volume and boost volume for the Space Echo preamp.
The centre toggle switch is a boost for the silicon stage; in the centre position is lowest gain (I use this sometimes to emulate a Proco RAT I use in one song live); on the left is a filtered, medium-high gain and on the right is high gain.
The right-hand switch (under the switch cover) is functional - though the toggle switch cover means you shouldn't trust the sprung switch snapping shut half-way through a gig; that's what it is there for, after all! In the 'up' position, you get a woolier, less filtered fuzz, but the default position is down for a more aggressive tone. If you don't want the switch cover, ask when ordering and I will remove it before shipping.
The germanium transistor is a hand-selected NOS instance of a soviet-era design that we've only got a few of, so this pedal is a strictly limited edition (unless we can find more like it!).
NB: be aware, that this pedal does not clean up with a volume knob or any of that nonsense. You'll notice there's no gain/drive control, and that's because the germanium stage is lower gain and the silicon higher. The interaction between gate and biasing means you can go from more extreme to more subtle, but a vintage fuzz sound is probably not possible with this pedal - and that's not what it was built for, anyway.
You can download the manual for the EVA here.