The Grandstream GXP2200EXT is the expansion module that has 40 additional display lines and can be used with the GXP2140 and the GXV3240.
The GXP2200EXT is a backlit LCD extension module supported by the GXP2140, GXP2170 and GXV3240. The module includes 20 dual-colored extension keys and 2 arrow keys for page switching (allowing each GXP2200EXT to support up to 40 contacts/extensions.). Connect up to 4 GXP2200EXT modules to compatible Grandstream phones for a total of 160 contacts/extensions.
The GXP2170 is an Enterprise IP Phone for users needing to handle daily high call volumes. The GXP2170 features up to 12 line keys and six SIP accounts on a full color 4.3 inch display. It also has a full duplex-speakerphone with HD audio capabilities for quality and clarity over voice calls.