Our all-in-one unit comes pre-assembled with back can and mounted transformer. It features quick-flip 70 or 25 Volt selector switch and an easy-select transformer wattage dial. The 8 individual wattage tap settings cover complete range of uses. This flame-retardant ABS unit also comes with insulated wires and built-in easy mount tabs for securing the unit. The MA Series is the ideal, all-purpose value speaker covering a wide range of commercial applications. The furnished 8 Ohm tap selector also means speakers can be kept on-hand for unexpected residential installation needs.