Polycom， Inc. VVX Color Expansion Module<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Compatibe with VVX 300 VVX 310 VVX 400 VVX 410 VVX 500 and VVX 600</li><li>28 multifunctional line keys configurable as line registration call appearance speed dial DSS or BLF</li><li>Dual color illuminated LEDs for line status information</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41E84F-QCbL.jpg" noproxy>