Comdial DX-80 Key Service Unit (Refurbished)The DX 80, Comdial's all in one communications system that's affordable, easy to use and can be loaded with great features like integrated voice mail, live call screening, auto attendant, and more (Requires expansion cards to achieve this level of functionality sold separately). The Comdial's DX 80 digital telephone system gets small businesses started with reliable, scalable communications technology. Fully expandable to 16 CO lines and 56 extensions