Aastra M671 Expansion Module
This keypad add-on makes an additional 36 softkeys available. It is compatible with the Aastra 6773, Aastra 6773ip, Aastra 6775 and Aastra 6775ip. Up to three M671 with 36 keys each can be connected.
Aastra M676 Expansion Module
This keypad add-on expands an Aastra 6775 or 6775ip by adding 20 softkeys (function and destination keys), each with three levels. The display is illuminated. Up to three M676 extensions can be connected.