Intertel 618.5115 ECX 1000 Display Phone (Charcoal/Refurbished)The 618. 5115 phone works with Inter Tel 3000 and Encore CX phone systems. Its speakerphone is a new full duplex design, for more natural conversations. It has eight programmable buttons for access to phone lines and the features you use most. It also provides display driven menus, Caller ID information and handsfree response to intercom calls, and communication by handset, headset or speakerphone. 4 line, 24 character display with six keys for