From Tech 21:

"While Bass Fly Rig v2 retains the same 100% analog SansAmp heart and cool effects, it now offers:

• A choice of SansAmp Character modes: 
  SansAmp Bass Driver DI for a variety of classic bass tube amp tones, or VT Bass DI with a more specific focus on Ampeg-style tones.
• Channel switching for two different Drive and Level settings.
  Go from clean to dirty, not-so-clean to not-so-dirty, very dirty to downright nasty, or any variation in between.
• Effect loop to facilitate incorporating additional outboard effects.

SANSAMP

with Choice of CHARACTER Modes and CHANNEL Switching

The expanded SansAmp section features 3-band active EQ and provides professional grade tweakability for any situation. The Character mode switch offers a choice of voicings within the bass tube amplifier sound spectrum. Channel switches between 2 different Drive and Level settings for when it’s time to kick it up a notch, or two, or three, or… There’s also a Bite switch which activates a presence boost to provide extra clarity to the top end.
OCTAVE and FUZZ Octave brings a re-invented pallette of expression with a crazy amount of possibilities, from Minimoog®-style synth to funky town. The controls interact so that you can get dynamically-filtered clean, fuzz, and octave, as well as octave and fuzz together. When Q is at minimum, Range becomes a high-cut tone filter for different versions of clean, fuzz, octave, and octave and fuzz together. You can then blend any of these combinations with your direct signal via the Mix control. But wait, there’s more. By bringing in some COMP, you can get infinite sustain like a keyboard bass. Whew.
CHORUS

Adds the choral voicings of two instruments. With a slight delay between, it adds thickness and space.

COMP COMP, for compression, utilizes old school, all-analog, FET-based technology from the ’50s and ’60s, which is inherently warmer, more transparent and musical.
CHROMATIC TUNER Simply hold down the Chorus footswitch to engage the Tuner, which simultaneously mutes the signal path.
FEATURES AT A GLANCE

• All-analog SansAmp circuitry with built-in speaker/cab sim. The SansAmp Tube Amplifier Emulation technology encompasses the entire signal chain, from pre-amp to power amp to speaker simulation. An integral part of the circuitry, the SansAmp speaker simulation will complement any type of guitar or bass speaker cabinet system. You can also place an external IR after a SansAmp to give additional flavor if you so desire. The SansAmp speaker sim is designed and individually tailored for a smooth, even response as would be achieved by a multiply-miked cabinet –without peaks, valleys, and notches associated with single miking and many IRs."

Brand new.