A Customer Review
"It does have stereo"
Other reviews claiming mono are wrong - when I first plugged it in I too noticed all the sound coming out of only 1 channel. However I then pushed the plug fully and firmly in and it works fully in stereo confirmed by several tests and hasn't reverted back.
Sound quality?
I bought 2 of these, since I have surround sound headphones (Zalman 5.1s) and good speakers (Klipsch Promedia 4.1s) to switch between. This is combined with an Audigy 2 ZS sound card so I was very concerned about losing any quality. After comparing several sources (mp3's, speaker tests, games) with and without the switch, I'm personally not able to discern any difference in sound quality so far in the hours I've used it.
In short works in stereo and can save a lot of hassle constantly changing plugs in the back of your PC. Definitely recommended.