On my external monitor (my PC a tower without its own monitor), there are two audio RCA inputs left / right. Thus so PC stereo sound reproduction from hard disk or drives. Now came a mono-VHS VCR, which uses the existing monitor the video cinch. But for the sound I needed an RCA input, but had no more free. Now does the RCA Y-cable to audio right, where now both devices are connected simultaneously. Perfect. No Umsteckenm more. (By the way, would have the second device also requires stereo, I would have at the left audio RCA also reingeseteckt a Y-junction.) It never run so both devices at the same time because I have to choose either source on the PC or recorder. The CLS-RCA Y-cable is a stable, great processing. We recommend !!