Siemens optiPoint 500 Economy Phone - Refurbished - ManganeseoptiGuide Feature Navigation Keys LCD Display with tilt 12 Program Feature Keys with LEDs Full Duplex open listening speaker for handsfree dialing Ringer and Handset Volume Keys Message Waiting Lamp Compatible with Hicom 150 H, Hicom 300 H, HiPath 3000 and HiPath 4000 communication platforms Note: The Siemens optiPoint 500 Advance Phone is only compatible with Siemens Telephone systems, and is not suitable for home use.