As its name suggests it simulates a lower tuning, tone 1/2 to 1 octave.
There is also a position that mixes the dry signal of the guitar + octave to give a synth sound like an octave.
9V 250mA input (adapter included)
Solid construction and good finish, the knob is comfortable to use and the switch and completely silent.
No need to book, it is very easy to use, you plug and play!
It makes the job to play with the stereo at home. Like this need to change tuning for each song! I remain on the guitar in E and I can go in Eb or D with a single click. Practice!
on the other hand I recommend for the studio or the stage, the sound is not clean, there was a kind of note "ghost" that is played at the same time that the detune note. I think the dry guitar signal is not completely cut off on the lower strings it goes on but it's pretty sharp and this quite annoying. In fact the solo sounds like playing with an octave and it's not what you asked ...
We also lose a lot of grain and definition especially with the distortion and drop in the more you lose (obviously!)
I find it expensive for what it does. For fun at home or repeats is not bad for the stage and the studio is clearly not up to par. A buy occas or when it is sold off.