The Aastra 536M expansion module is designed to increase the power and flexibility of the 5i Series SIP telephones. Up to three modules can be used with the 55i, 57i or 57i CT telephone to create a powerful, feature rich console option.

• Supported on the Aastra 55i, 57i or 57i-CT Phone
• Daisy-Chain up to 3 Expansion Consoles
• Add 36 Buttons
• Add up to 108 Additional Line Keys