Siemens optiPoint 500 Standard Phone - Refurbished - ManganeseMulti line digital telephone with display (tilts, with 2 lines x 24 characters) 12 feature keys with LEDs Integrated USB jack for efficient and cost effective CTI applications Full duplex on hook dialing for two way hands free communication optiGuide feature navigation keys Two volume control keys One modular bay for Easy add adapters Supports add on Feature Key Modules Works with Hicom 150 H, Hicom 300 H, HiPath 3000 and HiPath 4000 communication