Tone Remote Information
I haven't verified it yet, but it looks like the Motorola TNA200
L1548A P2 Connector Pin Out
Here is a link to a BatLabs post about the pin out of the connector that connects to the radio.
L1548 supports two channel selection.
The L1548 TRA is an IAI product [the MRTI people]. Here is the pin out of the P2 connector on the L1548:
P2 on the L1548A connects to the radio, normally a Maxtrac. The 3rd column in the table below shows the corresponding pin on the maxtrac 16 pin connector.
C200/ITR1000 Tone Remote Deskset
L1475 Tone Remote Deskset
TNA200 Tone Remote Adapter
TNA200 Tone Remote Adapter (back)