When the weather is dark・ the switch automatically enters the standby state・ giving the sound signal (50 dB・ which is equivalent to the clapping sound)・ and the power is on and off immediately. Lamp・ delay 30 seconds after the automatic power failure・ to extend the lamp life of more than 6 times・ saving rate of percent・ you can avoid the touch to find the fast break caused by injury・ but also to prevent the corridor lights were open・ off Human phenomenon. Sound and light control one light will be lit and then off (lamp self-test function