I have one of these boxes and the three buttons on top go like this. The box comes with already preprogramed sounds. The first button selects what sound you want to come across the radio that you are using. The second button allows the user to have the box let them know if they want the sound to activate when they key the mic up or after they unkey the mic. The third button allows the user to start the sound whenever they want to. An example for that is when I was using this box I was always on the SSB mode of my radio and when I singed off I would key the mic up and push the third button. I had the sound of a bomb going off and by watching my s meter I could tell when the sound ended indicating that I was going away from the conversation and shutting my radio down. I hope this info is helpful to you.
