Nortel Networks M3900 Key-based Expansion Module provides 22 keys for any combination of lines and features. The M3904 and 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. Use with your Nortel M1 Option 11C PBX system.
* Functionality of some features assumes availability and customer subscription to service provider offerings.
Local telephone companies: Buy Meridian Key Based Expansion Modules at wholesale prices for your rental phones program.