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. Compatible only with M3904 and M3905 Nortel Meridian digital phones. Requires either a single or double footstand (single footstand for one Key-based Expansion Module; double footstand for two Key-based Expansion Modules).

Can be added to the M3904 & M3905 phones Provides 22 additional line/feature keys Add up to 2 Key-Based Expansion Modules per phone for a maximum of 44 additional keys Fully programmable Each button shows status of other PBX extensions LED indicators View who is on the phone prior to transferring calls Footstand not included