1 BY ONE Easy Chime Wireless Doorbell Operating at 500 feet with 2 Plug-in Receivers, CD Quality Sound and LED Flash, 36 Melodies to Choose, White Long Range up to 500ft /150m - Either you are occupied in the garden or kitchen, you will always be easily informed when someone is calling from outside. FCC, RoHS certified 36 Different ringtones - There are 36 different ring tones with 6 levels of adjustable volume (High / Medium / Low) from 25-110dB 3 Notification Modes - Press the Sound-and-Flash Button for your favored notification modes (Sound/LED Flash/Sound and LED Flash) Do remember the LED Flash mode is available when you dont want to be disturbed Expandable &DIY -You can DIY to meet your requirement by pairing additional receivers and push buttons. 1 Receiver can pair up to 5 Push buttons Easy Installation - No batteries needed for the plug-in receiver. The push button can be fixed to the doorframe with the attached adhesive tapes. Besides, the push button is rated IP44 and weatherproof for outdoor use