This is a parametric equalizer from Empress. Really good for shaping your basic sound. To add more beef, clarity, punch or even more extreme shape like cocked wah or lo-fi sound.
I find this pedal is really good for recording session. I can tailor my sound in a specific manner. I use Empress ParaEQ with bass, guitar, acoustic. All results are great.
From the website :
The Empress ParaEq w/Boost EQ Pedal is designed to be a simple device that does its job extremely well. We noticed that the EQ section of many instrument amplifiers offer a very limited range of control. We designed the Empress ParaEq w/Boost to give musicians a powerful, musical, high quality EQ in a conveniently small package. The signal path of the ParaEq w/Boost is comprised of the highest quality components chosen for their transparency, powerful tone shaping capabilities, and low operating noise. With the Empress ParaEq w/Boost your instrument will still sound like your instrument, only better.