The small button turns it on, the knob is for volume, and the big button plays a random sound when you press it! There is a speaker in the bottom of the case.
Anyway, this box DOES NOT come with any of David Lee Roth's screams on it. You'll have to find those yourself. They aren't hard to find on the internet. I can't/won't distribute DLR's screams.
You can go to http://thegarage.dozuki.com for instructions on how to add sounds to this box.
The box is powered by a standard 9v battery, which is not included. You could also hack it to be USB powered, or powered by a wall wort style power supply, if you're not into portability. There's even a headphone jack inside the case, if you want to hook this up to a sound system or something.
Also, this box is just dying to be hacked. There's an Arduino in there, and a WaveShield. Check out http://www.arduino.cc/ and http://www.ladyada.net/make/waveshield/ to see all that these devices can do. With some simple coding you can make your button do anything!
NOTE: The power button and volume knob may vary from what is in the picture. They may be a different color or shape or size. They will function exactly the same. Sometimes I can't always get the same parts. If this is a problem, send me a message and I'll get you a picture of the one I'll send to you.
Press for the Roth Scream Box: