Expansion modules are designed to increase power and flexibility of the system phones. Theyincorporate several freely configurable keys. Each configurable key can be used to store individual call numbers or functions.

For the Aastra 5370/5370ip and Aastra 5380/5380ip there are two types of expansion modules available.

Expansion module Aastra M530

The Aastra M530 with designation labels includes 20 freely configurable keys with two memory places each.

Expansion module Aastra M535

The Aastra M530 with backlit display includes 15 freely configurable keys. The keys can be programmed on three levels.

For wall mounted terminals, the extension is limited to only one single expansion keypad.