Call coverage is a critical capability for administrative assistants & others who must monitor, manage, & cover the status of calls. This capability requires the ability to instantly determine the status of numerous lines beyond the six-line capability of the Cisco Unified IP Phone & eight-line capability of the Cisco Unified IP Phone. The Cisco Unified IP Phone Expansion Module 7916 extends the capabilities of the Cisco Unified IP Phone with additional buttons & an LCD display. With this expansion module, you add 12 physical keys with access to 12 additional keys through the page keys for a total of 24 buttons to the existing 6 buttons of the Cisco Unified IP Phone & the existing 8 buttons of the Cisco Unified IP Phone. You can use up to two Cisco Unified IP Phone Expansion Module 7916 modules with the Cisco Unified IP Phone.