Hi Bzumstein
yes, the SIP-EXP40 is compatible with the Yealink T46S.
look excerpt website
http://www.yealink.com/products_5...
EXP40
LCD Expansion Module
The EXP40 Expansion Module for the SIP-T46S, SIP-T46G, SIP-T48S and SIP-T48G, expanding the functional capability of your sip phone to a whole new level. It features a large graphic LCD. Two pages of 20 flexible buttons are shown on the display can be programmed up to 40 various features, the productivity-enhancing features include BLF/BLA, speed dialing, call forward, transfer, park, pickup, etc.
best regards
paolo
