1、ULTRA LONG WORKING DISTANCE: Our wireless doorbell has long distance transmission, high strength signal, and sensitivity, with a maximum opening distance of up to 100m. This doorbell ensures that you hear and answer the doorbell in a timely manner, and you will always be easily notified when someone makes a call from outside. 2、SIMPLE INSTALLATION AND EXPANSION: The wireless intercom doorbell is scalable, so you can expand almost any indoor or outdoor system, even to a set of 2 transmitters and receivers. 3、EASY TO INSTALL: Just stick our wireless doorbell directly to the wall with tape. Pairing outdoor bell with indoor bell by learning its code, one outdoor bell can pair with N indoor bells without interfering with other devices in your home or neighbors. 4、LOW POWER CONSUMPTION: Our two way intercom doorbell has an outdoor bell standby time of up to six months. 5、WIDELY USED AND ADJUSTABLE SPEAKERS: Our perfect wireless doorbell kit is suitable for homes, apartments, schools, villas, offices, warehouses, hotels, factories, hospitals, and more. Adjustable speakers provide clear and loud sound, which can be used as a mobile intercom.