1) The light use PIR senror
2) The light is only 30mm thick
3) Auto switching on when detecting people coming

 THe Led has super sensitivity within 3 meter distance; comes on automatically to illuminate the keyhole as you approach,making safe entry into your home.No more fumbling by your door in the dark,mountable light with built-in PIR sensor.Requires one AA battery.LED quantity     4pcsLED Brightness 10000 cdm(25°);1300cdm(120°)--(optional)LED life >80000HUse condition  Only darknessInfluence distance    <3mInfluence <60°Battery Use high quality "LR06"(AA)1PCS(not included in package)Self-test time 20sencondsAccessories 1)3M two-sided adhesive tape; 2)manualUse condition  Only darknessStand-by current <0.35mA (operating voltage:3V)Work current <60mA(operating voltage:3V)Delay time  If people leave,light will delay 5-7S turn offLight sensor  Bulit -in