KIDDE internal communication module smartcell v2 (2g/3g/4g), provides the option of remote connection for updates, sms / email, for internal connection within the smartcell control panel, includes a gsm antenna with 3 m cable and sim slot with support for 2g / 3g / 4g connectivity, requires the annual smartcell sc-94 remote services contract from 1 year, en54-21. voltage 5 vdc (from the control panel)