The VTech CM18245 Extension Desk set for the VTech CM18445 Small Business System is an expansion desk set only. It requires the VTech CM18445 main console to operate. The CM18245 uses DECT 6.0 technology, which provides strong protection against wiretapping and the best call range while not interfering with wireless routers. Plus, it makes installation a breeze. Simply connect the power cord and push the registration button to pair to the main console. The VTech CM18245 Extension Desk set for the VTech CM18445 Small Business System has its own digital answering system with up to 180 shared minutes of incoming messages, outgoing announcements, and memos. It also features individual caller ID/call waiting and 32-number speed dial.