The ESI 48 key telephone is one of the best selling telephone sets that ESI ever made.
The 48 key comes in 5 different models.
ESI 48 key DFP
ESI 48 key HDFP (Headset plug)
ESI 48 key HDFP BL (Backlit)
ESI 48 Key HDFP FD (Full duplex and baclit)
ESI 48 Key IPFP (IP telephone)
These phones have 30 programmable buttons and a dedicated voicemail key.
They also have an adjustable base.
Systems that are compatible are.
ESI S class gen 1 and gen 2..
ESI E class gen 1 and gen 2
ESI 50 and 50 L
ESI CS 100 and CS 200.