Description Module The SBM24 key module increases the line number for calls and functional keys on a phone Avaya 9600 series Suitable for IP phones Avaya 9608, 9608G, 9611G, 9641G and 9641GS IP Deskphone Provides 24 additional lines for incoming calls, outgoing calls and call functions No separate power supply required. However, using more than one button module changes the phone power class in Class 3 IP Office Compatibility 6.0 to 8.1 - Compatible with IP phones Avaya 9630, 9630G, 9640, 9640G, 9650 and 9650C. It can add up to 3 SBM24 modules by phone; up to 42 SBM24 per system. IP Office 9.0 or higher - Compatible with IP phones Avaya 9608, 9608G, 9611G, 9630, 9630G, 9640, 9640G, 9641G, 9650 and 9650C. It can add up to 3 SBM24 modules by phone; up to 42 SBM24 per system. Avaya Communication Manager R4.0 or higher - Can add up to 3 SBM24 modules for Avaya Communication Manager phone below R4.0 - Support for a SBM24 by phone