1988 DOD FX25B Envelope Filter USA-Made Vintage Guitar Effects Pedal – Mike & Mike's Guitar Bar
Amazon.com: MOOER Envelope Analog Filter Dynamic Auto Wah Pedal, Exaggerated slap back funk, Subtle sultry abience, Static frequency filter effects for Guitar and Bass : Musical Instruments
GFI System Rossie Filter Pedal – Chicago Music Exchange
Electro-Harmonix XO Q-Tron Plus Envelope Filter Guitar Effects Pedal | Guitar Center