Four-way Universal Intercom

You may make a four-way Universal Intercom connection with a couple of different configurations, 1) three SRLs and one non-Sena Bluetooth headset or 2) two SRLs and two non-Sena Bluetooth headsets.

You may have a couple of other four-way Universal Intercom configurations, 1) your headset (A), a non-Sena Bluetooth headset (B), another SRL (C), and a non-Sena Bluetooth headset (D), 2) your headset (A), a non-Sena Bluetooth headset (B), and two other SRL headsets (C and D). You may make the four-way Universal Intercom call the same way as a normal four-way intercom call.

1. You (A) may start an intercom conversation with the non-Sena Bluetooth headset (B).

2. The other SRL (C) may join the intercom by making an intercom call to you (A).

3. The non-Sena Bluetooth headset (D) may join the three-way intercom by making an intercom call to the SRL (C).

4. Now two SRL headsets (A & C) and two non-Sena Bluetooth headsets (B & D) are connected with the four-way Universal Intercom.

You may disconnect a four-way Universal Intercom using the same
way as you do in a normal four-way intercom. 

14.2.4, “End Multi-way Intercom”