Nortel M3900 Series Meridian Digital Telephones bring the functionality of Meridian 1 and Meridian SL-100 to the desktop with display-based interfaces, call log, self-labeling keys, and simplified administration. The M3900 portfolio offers five models and a variety of accessories to meet diverse requirements for features, ease of use, and productivity. Norstar M-Series Phones including the M7310, M7100, M7324 and M7208 are all for sale. Buy new and used business phone systems. But Direct Telecom specializes in the sales and support of both new and refurbished Nortel M-Series phones.