The de Lisle Speaker Cabinet AB Selector Switch allows you to toggle between two speaker cabinets connected to the same amp. If your amplifier has multiple output jacks for different impedance cabinets, you can connect a second output to the ALT Z jack and toggle between two cabinets connected to different impedance outputs on the same amp. There's also a remote input that will allow you to operate the switch from a distance with a simple TS latching switch.