• Master station in 20 and 4" station sizes• Built-in All Call, Selective Call, and Group Call• Push-to-talk at master or use handset• Group Call up to 5 subs at a time• Incoming calls remain lit until answered (max. 10)• Separate transmit and receive volume controls• Adjustable ring tone (melody or chime)• Automatic ringtone volume level (increases after 90 seconds)• Optional software for call event logging (NI-SOFT)