The CP400 is the mid-range phone for the budget-conscious professional user. Even the base unit features 16 programmable function keys with a three-color status indicator. It can be expanded with up to two KM400 key modules, each of which has 16 function keys. The paper label reduces costs and meets customer demands for many programmable keys. The energy-efficient design allows for the connection of two key modules within the PoE Class 2.