The GHP611 is a delicate IP Phone featuring one HD speaker on handset 2 SIP accounts/lines 3 programmable keys and 10 speed dial keys. It also support 3-way voice conferencing using full band Opus voice codec and advanced jitter-resilience algorithm that tolerate up to 30 packet loss without impacting voice quality. The GHP61X series is supported by Grandstreams Device Management System GDMS which provides a centralized interface to configure provision manage and monitor deployments of Grandstream endpoints. Note: This unit is hand set only without any power supply. Any power supply needs to purchase separately.