The Markworld Footswitch Dual can be used with the Big Bang and Little Marcus series heads. For the Big Bang Head one button on the Dual Footswitch controls the mute function (allowing you to tune silently), and the other activates the filters section. For the Little Marcus the two switches allow to turn ON/OFF the EQ1 and EQ2 sections. Compatible also with the discontinued TA 501, TA 503, MoMark LMK and Studio Pre.