2 purposes:
1) "Someone asked me to create a simple Beeper Box to allow a non-verbal switch user to do Morse Code with 1-2 switches. This device does that! 1 switch for dot/dit, or 2 switches for HIGH pitch/low pitch." RJ
2) A simple switch tester.
Comes with batteries. Switch(es) not included.
The Beeper Box is the yin, to your yang. You've found what you're looking for.