ESI Phones come in a variety of variations to be used with their line of IVX phone systems and ESI Communications Servers. The ESI phones come in analog (ESI EKT-A), digital (ESI H DFP), and IP (ESI IPFP2) versions to meet whatever communication needs you might have. ESI phones can be purchased in various key configurations based on the needs of the user and system. ESI phones come in 12, 24, 40, 48, and 60 key configurations. Both the older legacy phones such as the IVX DP1 and the newer ESI 60IP phones are available.