Display – Paper. Line Keys – 40 illuminated bi-color LED keys programmable line keys. Daisy Chain – Expandability up to 3 modules (Daisy-chainable for a total of 120 contacts (3 x 40). Compatible Phones – VVX business media phones (VVX 300/400/500/600). Power – Provided by the host VVX business media phone. Contents – Includes AUX cable and attachment hardware.