OEM service, sound custom-made ,press a button ,it sounds or lights or sound with light ,or flashing . A, sound keychain-sound module for promotion gift or entertainment 1,custom-made (sound,music,melody,housing color,housing size,shape,function,packageing)proceeding steps:a, sending me the sound file you wanted ,or I recommend to you the sound when you tell us you need which kinds( eg, merry ...