Brand: Helios. MPN: AS-SS4. Need to distribute a stereo speaker level signal to multiple listening zones? The Helios AS-SS4 4 Zone Speaker Selector is the solution. It features a manually activated impedance protection switch. Turn it on to prevent the impedance to your amplifier from dropping below 5 ohms regardless of the number and impedance ratings of your speakers. Turn it off when it s used as a part of a system incorporating impedance-matching volume controls allowing you to get the most out of your amplifier. For in-wall installations use CL-2 or CL-3 rated cable for compliance with local building codes. When connecting a speaker and amplifier be sure to maintain the correct polarity between the amp the speaker selector the volume controls and the speakers.