Product review (4 stars): Great At Keeping Our Dog Downstairs.
This product works great. We got it to deter our big dog from going upstairs to ve destructive. It comes with a micro SD card, which I didn't know and had already bought one for it. I still used our own because didn't want to plug something I didn't know where it came from in to our computer.

You take the micro SD card, put it in to your computer and record yourself (YOU CANNOT RECORD DIRECTLY TO THE UNIT). You can use your computer to record whatever you want and then save it to the SD card (like yelling at your dog to get back downstairs) and then put it in the unit and it works great! Make sure you record a MP3 file only as it will not play a .wma file. Also, the loud setting is very loud, which is great for us.