The QED SS40 4-way parallel speaker switch enables you to connect and switch four pairs of speakers in parallel

When you want to use the full power of your amp and get a louder setup simply switch in the second, third or fourth pair of speakers

Parallel wiring of speakers delivers more power to each of the speakers due to the equivalent resistance of the circuit being less than that of the individual speakers. For instance, two 8 ohm speakers would have an equivalent resistance of 4 ohms when connected in parallel. So you don't damage your amplifier calculate the combined impedance of the speakers you will be connecting in parallel to be sure it is not below the minimum impedance requirements of your amplifier.