ETR 18/ETR 18D
The ETR 18 does not include a display. The ETR 18D includes the display.
ETR 34D
The number of ETR 34D phones supported is limited to a maximum of 4 (with a maximum of 2 per ETR6 base card).
PARTNER User Guide
Page 8
IP Office PARTNER Version
- Issue 1b (22 February 2010)