NEC I Series Manual page 6

T here is an i-Series telephone or combination of
telephones to meet all your telecommunication
needs efficiently, totally and economically. The i-
Series telephones can feature interactive Soft Keys,
built-in Speakerphone and Wall/Desk Stand, and a
choice of analog, data, and Off-Hook Voice
Announce snap-in modules.
Digital Single Line
34-Button Display
34-Button Super Display
28-Button Display
110-Button
DSS Console
24-Button
DSS Console