Features: Clean boost module specially designed for using with BIYANG LiveMaster Series modules mainframe units LM-4/ LM-7/ LM-10.(mainframe units sold separately) With true bypass and will make your sound clearer and more meaningful; 12dB active low/high EQ. BOOST knob: to adjust the gain volume of the boost; 2-way toggle switch: PRESET--modes that operate as presets in the same manner as conventional Livemaster pedals, LIVE-- can be used as a separate channel independent of preset mode. Special spring locking design makes it easy to install and remove the module from the mainframe unit, flexible and convenient to use. Metal touch points design greatly reduces the noise from pedal linked cables and maintains the line signal intensity at the same time.