Snom Expansion Module v2.0 Black 1268 for the 300 series Phones
With the snom Expansion Module, your snom has the best features to meet the requirements of executive and administrative staff that require high call coverage and flexibility from communication systems. The Version 2.0 of the expansion module allows to daisy-chain up to 3 expansion modules. So you can use up to 138 buttons.
Snom expansion module