The Plug and Play eliminates the confusing switch found on most stereo cabinets. Just pick your impedance and plug in. Label is set at the common Ohm Mono and 8 Ohm Stereo. Ready to install with a steel dish, wires, and speaker connectors. Direct replacement for many existing small jack dishes. Can be used for the following configurations: 4 ohm mono 8 ohm left + 8 ohm right stereo 8 ohm left only mono 8 ohm right only mono 16 ohm mono The Plug and Play can be used with two 8 ohm speakers, four 4 ohm speakers, or four 16 ohm speakers.