Part of the Cisco Small Business Series, the SIP-based Cisco SPA 504G 4-Line IP Phone has been tested to ensure comprehensive interoperability with equipment from voice over IP (Vo IP) infrastructure leaders, enabling service providers to quickly roll out competitive, feature-rich services to their customers. With hundreds of features & configurable service parameters, the Cisco SPA 504G addresses the requirements of traditional business users while building on the advantages of IP telephony. Features such as easy station moves & shared line appearances (across local & geographically dispersed locations) are just some of the many advantages of the SPA 504G. **PSU Not Included**