I bought this new as one of the first “one pedal does it all” devices, released by Zoom in 2013.It has over 100 guitar effects including distortion, compression, modulation, delay, and reverb.  An expression pedal is built into the unit allowing foot control of a number of effects.   Also included is a built in tuner, a 30 second looper, and even a 68 pattern drum machine.   This pedal also does amplifier modeling.   A lot going on in this little pedal.  It runs on 4 AA batteries but can be powered with 9 volt volt power supply (not included).  A USB port is provided for software/firmware updates. An auxiliary input jack is provided to allow the insertion of external music. This signal bypasses the effects section and is mixed directly with the output.  There is a single guitar input jack and a single output jack that can be used either for headphones or to pass the output to a guitar amp or PA. The display is backlit.   Pretty much all of the bases are covered in terms of guitar effects in this one pedal. Can be used for live performances, but is probably best suited for home practice or recording.