1) wireless doorbell with audio intercom, 2) DECT, cordless telephone, 3) Unlock module, 4) Frequency: 1.8G, Technical Specifications1. CE ( ... EMC LVD TBR6)2. Standard: Digital Enhanced Cordless Telecommunication3. Frequency Range:1800 ... Use the handset to unlock the door (optional)4,Waterproof with IP 655,Full hands-free speaker6,High ...