here is my collection of three pairs of Marchand Electronic crossovers. My plan was to build a 4-way crossover. Here is whats included: All manuals needed and related Marchand literature One PS-10 Dual 15 volt regulated power supply, which is correct power supply for all three crossovers. Pair XM-1 24 Db/octave cross over with extra frequency modules Pair un-assembled XM-16 48 Db/octave crossover network Pair XM-44 Embedded crossover network The PS-10, XM-1s, and the xm-44s are in good working order. The XM-16s are new and un-assembled. Each are a pair of single modules, making them 2 ways. The modules and power supply is what the listing is for. There are no knobs or switches or pots. I hope someone is able to finish the project my health put an end to.