Walkie talkie works on the simple physics principle, where we are converting audio signals into radio signals via antenna, later other walkie talkie will decode signals of radio into audio signals, then voice is heard. Build quality and antenna quality determines the quality of voice heard in walkie talkie conversations. Unscrew two walkie talkies and insert 9 V battery in each( Included) . We are ready to use them. There are two buttons on each walkie talkie. When you are speaking, always press left side button (which activates the transmitter).Operate right side button to either switch on or switch off the unit .