The ESI E class or72E is a flexible system capable of using different cards.

The total configuration is 24 lines and 48 digital telephones.

The Cards that can be used are.

E2 612 card( six lines 12 digital telephones)

E2 684 card (six lines,8 digital and 4 single line)

E2 D12 card (12 digital)

E2 A12 card (12 analog.)

E2 DLC 12 card (12 digital and a T-1 circuit)

E2 IVC card ( supports up to 12 local or 12 remote 48 key IPFP RMT telephones.

The digital phones that work on the system are the 48 key HDFP and the 24 key DFP.

The system can also have a NSP port for programming.