The D7 expansion module features 18 multicolor LED keys which can be programmed with all functions available known from snom phones like line, speed dial, busy lamp field, presence indication, and many more. The call or presence status of your contacts is presented by the D7€™s multi-color LED keys at any given time. The high-resolution display provides a perfect visual interface which can be easily configured and labelled via the phone€™s web interface or directly on the phone itself. Using the D7 could not be easier: simply connect the USB cable and it€™s ready to use. Even power is supplied by the host phone. Three D7 expansion modules can be daisy-chained to add up to 54 function keys to your phone. The last D7 in the chain offers a USB port to connect other peripheral USB devices to the host phone. Thus, A USB headset or a WLAN stick can be used. The D7 is the perfect addition to any snom 7-series desk phone Features - 18 highly configurable self-labeling LED keys - High-resolution black & white display with backlight - Daisy chain up to 3 modules - Plug and play - Power supplied by phone via USB port