The 2703U is the latest style Universal hands. Technically the same as the 2603U.
This universal telephone is compatible with the majority of telephones produced by the major world producers. It has a door-opening push button and a free button for various uses.
The volume of the microphone and the loudspeaker can be adjusted.
It has electronic call or mechanical buzzer options.
A = Door opener
B = microphone
C = Common
D = Call ( electronic or mechanical)
E = Loudspeaker
call selector – E – Electronic bell M = Call with buzzer.
Can be used to replace a number of older model Comelit handsets as well as handsets of other manufacture. 2603U compatibility chart