Optional additional package for all communication systems of the types ES 5xx up, ES 54x, ES 6xx, ES 7xx [each from system firmware 1.7], ES 7xx plus and ES PURE-IP! Scope of services: enables the activation of 6 additional voice boxes that can be freely assigned via call distribution. Including Voice To Mail function for sending the recorded messages as a wav file to a desired destination address. System expansion to up to 12 (ES 542) / 18 (ES 546 and ES 548) / 24 (ES PURE-IP) / 30 (ES 628) / 60 (ES 730, ES 730 plus) / 120 (ES 770, ES 770 plus) voice boxes possible!