AT&T MERLIN LEGEND Release 2.0 Equipment And Operations Manual page 123

Hardware Components
Figure 2-19. Analog Multiline Telephone Headset
Speakerphones
Separate speakerphones can be connected to single-line sets
Model S202A Hands-Free Unit (HFU) for analog multiline telephones allows calls
to be made and received without using the handset. If an Auto Answer
Intercom button
on automatically
The S203A
compatible with any 2500 or 500 phone and requires its own local power.
Newer units may be shipped with a transformer, but older units require a
KS21239L4 transformer and 248B adapter to be ordered separately.
The
4A speakerphone consists of a 108AA loudspeaker set, a 680-type
transmitter, an 85B1
speakerphone must be used with a 2500SM telephone.
is programmed and activated on the telephone, the HFU goes
when a voice-announced call is received.
speakerphone allows voice transfer without
power supply, and a 223C connecting block. The 4A
using the handset. It is
Adapters and Adjuncts 2-49