YDM4109A comes with a voice guide feature that provides the status of the lock and details on how to personalise each feature and mode to suit the convenience of the user. In using a smart lock such as the YDM4109A, you can cast a wider security net to safeguard your home against burglary or intruders. No longer do you need to worry about forgetting to lock the door before leaving for work or vacation. YDM4109A is implemented with DoorSense™ technology* that lets you know if the door is closed or left ajar. And if the door has been left ajar, the auto locking system will automatically lock the door for you within a 5-second timeframe.