1) wireless doorbell with audio intercom, 2) DECT, cordless telephone, 3) Unlock module, 4) Frequency: 1.8G, 1.9G ... Specifications1. CE (EMC LVD TBR6)2. Standard: Digital Enhanced Cordless Telecommunication3. Frequency Range:1800~1900MHz4. Channel Bandwidth:1.728MHz5. ... +/-10%, 50-60Hz)Outdoor station: 2 C size alkaline batteries Features1,Support all DECT phone features2,Use the handset to ...