Sealed and mint copy of Shure’s 1973 third Audio Obstacle Course traceability rest record, on TTR-110. The Shure microphone company made a handful of these test records, starting in the early 60s, in the midst of the hi-fi revolution of the time, of which I believe this was the last. A rare relic from the best era of audio equipment and hi-fi sound. A perfect copy, impossible to beat.