Wireless intercom doorbell - 1 outdoor doorbell can be paired with 1 indoor doorbell, the perfect combination allows you to communicate with visitors at your door. Intercom Two-Way - When someone presses the call button on the outdoor unit, the indoor buzzer will ring immediately to remind you. You can press the answer button to talk to someone outside. Clear voice - Built-in high-sensitivity microphone and speaker, the signal 2.4 GHz provides clear and fluent sound effect when communicating. Effective transmission distance up to 300 meters. Easy to use - Ultra mini size ensures perfect portability and easy installation, small and beautiful, easy to install. Suitable for home, factory, hotel, hospital, supermarket and office. Product transmission distance: 200 meters in open space; 5-50 meters if there are obstacles. Feature 1. The frequency of use of this product complies with national regulations and will not produce harmful electromagnetic interference. It can be used universally. This device complies with FCC, CE and CCC rules and regulations. 2. The outdoor unit is easy to install and battery-remove, using 4 AA batteries (batteries not included), and the indoor unit uses a rechargeable lithium battery. The outdoor chime is powered by 4 alkaline batteries for easy battery replacement. 3. The outdoor unit has a long service life, and 4 batteries can be used for more than six months. Low power consumption, outdoor bell standby time up to six months. 4. Speaker sound, adjustable volume, changeable ringtone, clear intercom sound quality, can be used for mobile intercom. The speaker is adjustable, the sound is clear and it can be used as a mobile phone walkie-talkie. 5. Long working distance, the maximum opening distance is 200 meters. Ultra-long wireless distance up to 200M. 6. Easy to install, directly stuck to the wall with 3M glue. Easy wall mounting with 3M adhesive tape. 7. Through code-to-code learning, one outdoor unit supports N indoor units without interfering with each other and without changing the code. By learning the code, the outdoor chime can be paired at the interior chime. An external ringtone can be paired with N internal ringtones without interfering with each other. 8. Exquisite and small, beautiful and generous. Size: 100*60*14.8mm Note: The data is all manual measurement, please allow 1 - 3cm error, due to the difference in light and display, there will be some color difference, depending on the physical object received. Delivery Quantity: as shown in the main picture.