HP Poly VVX EM50 Expansion Module for VVX IP PhonesThe Poly VVX EM50 IP Phone Expansion Module is easy to install and designed exclusively for the Poly VVX450 business IP phone (sold separately). Its an optimal solution for telephone attendants, receptionists, administrative staff and other power users who manage multiple workflows or simultaneous calls on a daily basis. The VVX EM50 extends the functionality of your Poly VVX450 business IP phone with multifunctional line keys that can be set up as