AT&T 2-Line Dect 6.0 Digital Accessory Handset DECT 6.0 technology is a newly available frequency band that provides improved range without needing to boost the power. The sound quality on our DECT models is superior to existing 2.4 GHz and 5.8 GHz models and enables the user to talk anywhere in their home or office without interference from a wireless network. This proven and reliable technology has been in use for a number of years in Europe and has proven to provide brilliant quality of voice and sound, high protection against eavesdropping and better range than 2.4 GHz and 5.8 GHz phone systems.