... dress .The on/off is a switch for power. 1) when you push the on/off to "on" ... the frequency is slowly. this time, if you push the button switch, the flashing frequency will be rapid. but this ... dress not light flash. this time , if you push the button switch, the dress will be flash. but the frequency ... just continue about 15 seconds. Replace batteries 1) push the ON/OFF to "off" position.2) loose ...