The LED lights up green to indicate that the door is unlocked and returns to white as soon as the lock is reset (at resting state).LED driven by an access control. The LED can be controlled by a stand-alone access control system, provided that a timer is integrated in the keypad.In this case, the opening is obtained by simply pressing the finger on the stainless steel surface of the ABS push button, but it is not necessary to manually keep the stainless steel button pressed to gain access. If the timer on the keypad is set to 30 seconds, for example, this gives you time to leave the building with your hands free.