The Grandstream GXP2135 is a multi-line high-performance phone that will meet and exceed all of your enterprise level IP Phone needs. With key features such as Power over the Ethernet (PoE), built-in Bluetooth, and dual Gigabit ports for fast and clear IP communications, why look anywhere else? 
Grandstream GXP2135 Multi-line high performance IP Phone Overview
With 32 virtual BLF/speed-dial keys, up to eight lines/line keys and four SIP accounts, the GXP 2135 is the best IP Phone for workers with a lot on their plate. The GXP2135's built-in Bluetooth easily syncs with mobile phones and headsets with ease as you enjoy HD audio and a 2.8 inch LCD color display. The GXP2135 has 4-way conferencing capabilities and supports EHS compatible Plantronic's headsets. If used with Grandstreams UCM series IP PBX appliances, you can enjoy even more features such as Zero-Configuration provisioning, 1-touch call recording and more. 
 
Grandstream GXP2135 Multi-line high performance IP Phone Features and Specifications
8 lines, 8 dual-color line keys (with 4 SIP accounts)
4 XML programmable context-sensitive soft keys
Dual switched auto-sensing 10/100/1000Mbps Gigabit network ports
32 digitally programmable & customizable BLF/fastdial keys
HD audio to maximize audio quality and clarity; full duplexspeakerphone
Built-in PoE to power the devices and give it a network connection plus power supply included 
Built-in Bluetooth for syncing headsets and mobile devices for contact books, calendars & call transferring
Supports EHS compatible Plantronics’s headsets
Automated provisioning options include TR-069 and XML config files
Built-in USB port for importing and exporting data
4-way audio conferencing for easy conference calls
TLS and SRTP security encryption technology to protect calls and accounts
Auxiliary Ports: RJ9 headset jack (allowing EHS with Plantronics headsets), USB
Base Stand: Yes, 2 angle positions available, Wall Mountable