exactly, that is the Mutron Octave Divider.
that sounds like just the Mu OctDiv with the ringer ON with the mix just slightly on the guitar side vs the effect side as you can still hear a good chunk of the base guitar tone. towards the end of the jam you can hear him roll the guitars tone control all the way to the extreme bass side also.
this setting sounds great with the boss ds1 or series 2000 mxr dist+ in front of it as well.
Disclaimer: I make and sell Buffers. I also sometimes Modify, Build and sell preamps and amplifiers. My opinions are not intended to be sales pitches. I am a one man shop and prefer to spend time with my wife and family, i work full time on call and love to spend my spare time doing other things. I only make, modify or build things for those that seek them.