I ordered this from Amazon and it works as advertised. Better still, it has DRAMATICALLY improved the sound of my player in the car. With my old cassette adapter, the volume was very low (even with the player turned all the way up) and the bass/treble was messed up, so I had to make all sorts of adjustments whenever switching between my Rio player and the car radio. Even with all that it never sounded right. With the Koss cassette adapter, I actually had to turn the volume down on the player to match the radio volume, but now that I've done that I just plug it in and go (no more messing with all the settings) and it sounds great.

I think the people complaining here that this is a piece of junk because the power adapter didn't fit their player are misguided. If Amazon recommended this as an accessory for your player and the plug does not fit, then you should let Amazon customer support know they are making an erroneous recommendation. Most of the low ratings on here have nothing to do with the quality of the product when used with compatible players. For my RioVolt SP90, it has met and surpassed my expectations.