The Adcom GFS-3 is a high-quality speaker selector switch that gives you the flexibility to run up to 3 pairs of speakers off of a single pair of amplified speaker outputs (up to 200 watts per channel). When selecting and using multiple pairs of speakers simultaneously, the protection circuit built into the GFS-3 is designed to protect both speakers and amplifier without sacrificing sound quality.  The GFS-3 was specifically created to prevent the harm that can result from having multiple pairs of speakers present too low an impedance load on your amplifier; this condition can cause your amplifier to cut power output and result in unpleasant distortion. Pushing the “Protection” button on the GFS-3 inserts added resistors into the amplifier-speaker line so that the amplifier is able to work efficiently within its operable impedance range, protecting your amplifier and speakers and preserving audio quality.