Features: 1.[Multi Functional] This infrared doorbell has five functional reminders: welcome, doorbell, alarm, color light and night light. With change battery memory. 2.[Colorful LED Light] Welcome doorbell is designed with colorful LED lights, adjustable brightness, available in different colors to distinguish multiple access. 3.[Multiple Application] Infrared motion sensor doorbell is widely used in various stores, high end clubs, hotels, offices, factories, families, villas, etc. 4.[280m Remote Range] Wireless welcome doorbell can transmit from a long distance, open space up to 280m/918ft, suitable for larger places and higher floors. 5.[Large Speaker] Doorbell adopts 40mm/1.57in speaker for independent alarm, with adjustable volume up to 113dB, which can effectively scare off thieves. 8 chord music chip, pleasant sound. 6.[Sensing Angle And Distance] Infrared doorbell sensing angle is 100 degrees horizontally and 15 degrees vertically. Sensing distance is 2 to 8m ( and ambient temperature related). specification:Item Type: Infrared Doorbell Material: ABS Transmitting and Receiving Frequency: 433.92MHz Operating Ambient Temperature: Receiver : -10 ~ +60 Infrared Detector : 10 ~+33 Working Environment Humidity :