DECT 6.0 Cordless Digital Answering System with Caller ID and Three Extra Handsets and Charging Cradles. Advanced DECT 6.0 technology operates on the newly released 1.9GHz frequency band. Uniden DECT incorporates "listen before transmit" technology that avoids interference with many household products, such as baby monitors, microwaves and WiFi. As a result, these phones offer enhanced voice clarity and crystal clear digital sound quality. DECT also offers high security and voice protection as well as longer battery and battery standby life.