The AI-121 eliminates unwanted anomalies and artifacts from audio signals transferred between equipment.  Anomalous and intermittent behavior can regularly occur in electronic products.  Equipment manufacturers are concerned, yet are not always able to replicate this behavior, and therefore determine the cause.  The AI-121 isolates and passes on the audio signal, without the artifacts.   The AI-121 has multiple uses:   The AI-121 is line level, so you may find uses we may have not even thought of!   Available with standard RCA or XLR connectors   Features massively improved sound quality, including:   SWITCHES: -HIGH / LOW Switch:   HIGH = +6 dB     LOW = Flat or 0dB   -GROUND / LIFT Switch (only in RCA version):    SPECIFICATIONS: -Distortion (THD) @ 1kHz, +0.0dBu = 0.001% -Response, ref 1 kHz @ 10 Hz = -0.1dBu -Response, ref 1 kHz @ 20 kHz = +0.05dBu -Response, ref 1 kHz @ 50 kHz = +0.25dBu -CMRR (Common Mode Rejection) @ 60 Hz >95dB