Line 6 Filter Stompbox Modeler The FM4 Filter Modeler, part of Line 6's award winning line of Stompbox Modelers, gives you an array of vintage and new effects from just a wee bit odd to full frontal freaky! From the gentle auto-wah of an envelope filter to the complete wackiness of mutated VCO controlled ring modulators, FM4 can get as strange as you wanna be. 4 completely programmable presets available at the tap of a toe. No more need for multiple pedals for multiple effects. True Bypass switching, so your direct tone is exactly that; direct from your guitar to your amp. Expression Pedal Input - for real time control of all effect settings. Also the ability to morph between settings lets you create effects not possible with the originals. Nothing but knobs. No menus, no multiple button contortionist gymnastic moves, just twist and go. Stereo inputs and outputs Runs from batteries