Geezer Butler

In the YouTube video "Geezer Butler Bass Rack Rig - 'Know Your Bass Player' (3/3)" by Which Bass, Geezer Butler is shown using the Boss LS-2 Line Selector.

This post on Dunlop's Facebook page reads, "Here's a great clip of Geezer Butler on stage at the Ozzy and Friends show, at Hartwall Arena in Helsinki, Finland last night. Geezer kicks off 'NIB' with his trademark bass solo, using Dunlop's 95Q Cry Baby wah pedal, and it sounds awesome!"

In the YouTube video "Geezer Butler Bass Rack Rig - 'Know Your Bass Player' (3/3)" by Which Bass, Geezer Butler is shown using the MXR MC401 Boost/Line Driver as part of his bass rig.

"The first ever signature Cry Baby Bass Wah is specially designed to retain low end frequencies while allowing an aggressive midrange to cut through the mix."

In this Instagram Post you can see Geezer Butler with his Signature Wah

Geezer Butler has been using the Tycobrahe Parapedal wah pedal since the 1970s, similar to Tony Iommi. During Black Sabbath's reunion in 1998, he switched to the Cry Baby Wah 95Q, as noted in performances like "Bassically/NIB." This is evident in the live performance of "Heaven And Hell - The Sign Of The Southern Cross" from 2007, available on YouTube.

Behind Geezer, on top of the amp, you can spot an EXH pedal with sliders. My best guess is that this is a Microsynth

Geezer Butler uses the Ashdown Engineering Ashdown Geezer Butler Pedal of Doom, as it is his signature guitar pedal with his name on it. According to Sweetwater, this pedal is specifically associated with him.