The Meridian M3900 series expansion module provides 22 keys for any combination of lines and features. The Meridian M3904 and Meridian M3905 each support up to two expansion modules, for a total of 44 additional keys. The Key-based Expansion Module is the perfect option for busy receptionists, administrators, and managers.
Mnfr. Part #: NTMN37
Use with your Nortel M1 Option 11C PBX system