The Poly Edge E expansion module can help you reduce the number of lost customer calls, shorten transaction times, and support more accurate call routing. Super-charge your Poly Edge E400/E500 series phones with 22 multifunctional line keys that can be easily set up as line registrations, call appearances, speed dials, direct stations or busy lamp field keys. Setup is a Plug-and-Play snap, with power and signalling provided by the host phone. Screening, dispatching and monitoring calls has never been easier.