Feature: 1. 【Wireless and Far Transmission】Ring chime features RF433 infrared transmission, no internet and WiFi required. 300m/984ft ultra-far transmission range. 2. 【Real Time Intercom】Real-time calling and answering, anti-interference encrypted call, clear sound quality with 4 adjustable volume. Outdoor chime is IP44 waterproof, simple installation, no wiring and no drilling required. 3. 【One Touch Operation】One-touch calling and answering, easy for child and elderly use. More protection and safety for whole family alone at home. 4. 【One to Multiple Indoor Units】1 outdoor chime can connect multiple indoor units(This product only 1 indoor chime include), press the doorbell, all indoor units will ring at the same time. Besides, indoor units can talk to each other, convenient for family members to communicate in real time in different rooms. 5. 【Type-C Charging and Long Standby】Convenient Type-C charging port and indoor unit with charging base. Both outdoor and indoor chime built-in 800mAh rechargeable lithium battery, indoor unit can use 3-7 days of each charging, outdoor chime with 6 months using time after full charged. Specification: Specifications: Color: Black / White (optional) Main Material: ABS Charging port: Type-C Battery capacity: 800mAh(each) Power: 0.5W Out door chime size: 5.1*2.4*10cm/2.01*0.94*3.93in Indoor unit size: 5.6*2.4*11.9cm/2.20*0.94*4.68in Weight: About 300g/10.58oz Package List: Package List: 1 * Doorbell 1 * Chime 1 * Back panel 1 * Charging cable 1 * Adhesive 1 * Set of screw 1 * Manual