Connect this footswitch to the footswitch jack of the Mackie ShowBox using a 1/4” TRS cable, and you'll have instant hands-free control over ShowBox performance features. The button on the left controls the looper, and it works exactly the same as pushing the looper button on the breakaway mixer. The button on the right mutes and unmutes the FX, just like double-tapping the FX button on the breakaway mixer... except you can do it while strumming! The FX footswitch also mutes/unmutes any pedals connected to the external FX send and return jacks.