The Big Muff is sort of camouflaged but it is resting under Brian's hand is once seen is noticeable by its angled face, tank green, and large silver round on/of toggle. And of course the knobs that are immediately recognizable.
'Yeah, I also have a Big Muff which I use. This one’s only about two years old, a Russian one. I like it, though a lot of people don’t like them. They are ugly. I’ve always used them though, love them'
An Electro-Harmonix Green Russian Big Muff Pi can be seen on [this](http://www.guitargeek.com/david-dederer-pusa-guitar-rig-and-gear-setup-1993/) detailed gear diagram of Dave Dederer's The Presidents of the United States of America stage setup.
In this interview with Total Guitar, Andrew Stockdale mentioned that when they were recording, and perhaps after, the first EP, he used a Russian Big Muff Pi along with an assortment of other amplifiers and a 70's SG electric guitar.
Here's a picture of Robin Finck of [Nine Inch Nails](http://equipboard.com/band/nine-inch-nails) and [Guns N' Roses](http://equipboard.com/band/guns-n-roses), posing with his pedal board, including the Electro-Harmonix Green Russian in the middle, on the top row.
It have more bass than the NYC one. For me it sounds better. This is a piece of history. EHX sure did a big mistake when they stopped the Russian labeled series and called green muff a bass one. It is confusing.