1、Sensitive Response: The doorbell sensor uses advanced sensing technology, can trigger automatically without pressing a button or pressing the bell when someone approaching the door. 2、Various Use: This doorbell greeting sensor is suitable for various occasions, such as home, shop, office, hotel, can be used as the welcome bell to give your guests a friendly and professional welcome. 3、Unique Design: The welcome doorbell alarm sensor has a simple and stylish exterior design to match various decorative styles, can not only provide practical functions, but also add decorative effects to your doorway. 4、Easy to Install: This doorbell warning sensor is simple to install and does not require any wiring, can simply use the back sticker provided to hold the doorbell in place and then install the battery. 5、Multiple Ringtone: The doorbell greeting alarm sensor offers a wide selection of ringtones to choose according to your preferences, the volume can be adjusted to suit different environments and needs.