1 Frequency of Doorbell is in line with the national regulations, will not produce harmful electromagnetic interference. 2 Battery take-in and take-out easily for outdoor machine, using 4pcs AAA batteries, and service life can up to four months, but the battery is not included. 3 The indoor machine doesn't need batteries, and it is connected with USB data cable. 4 Volume adjustable and ringtone changeable, the voice quality is clear and the speaker sound is loud. 5 Installed easily, can straightly stick doorbell to the wall with adhesive tape and less time consuming. 6 Using learning code to code, an outdoor machine support many indoor machines, non-interference.
What's in the box
1 x Wireless Intercom Doorbell
