Features: - Configure remote control, more convenient to use, remote mode switch music selection, volume adjustment. - Three modes. Welcome mode: 6 kinds of human welcome words; Doorbell mode: 45 chord music; Emergency alert mode. - Applicable to various places, shops, clubs, hotels, offices, factories, homes, villas, etc. - Long-distance 280m transmission, up to 280m in an open field, suitable for larger places and higher floors. - Adjustable 5-level speaker volume, easy to deal with various occasions. Specification: Working range: 280M (provided by factory laboratory test). Music selection: 6 welcome words and 45 i-ring music. 1 emergency reminder. Volume selection: 5 levels of volume (adjustable mute). Power supply voltage: receiver 110/220v. Sensor 3 AAA batteries (Not included). Micro USB power supply. Sensing range: 2-8 meters (related to ambient temperature). Dimensions: Sensor: 82 x 45 x 74mm. Receiver: 84 x 52 x 29mm. Scope of application: family commercial residential areas, office buildings, Hospitals, restaurants, factories and other places. Package Included: 1 x Receiver. 2 x Sensor. 1 x Remote control. 1 x Micro USB power