Disino 1/4 Pollice TRS Stereo Y-Splitter Cavo di Inserto, 1/4 Pollice Jack Maschio a Doppio 1
It's a way to insert a component (like a compressors, reverb components, etc.) directly inline with a preamp by using a single 1/4" jack. Connect the TRS plug into the "insert" jack of your mixing board.