" Wireless GSM intercom system no range limit! " Dials up to 3 numbers in sequence when call button is pressed (mobiles or landlines). " Up to 8 button systems available for multiple homes or apartments sharing a single entrance. " User can open gate or door by pressing * on telephone keypad. " Caller ID access for 100 users, and password mode for numbers which are not saved. " Module housed in weatherproof enclosure, complete with wall mount antenna. " Excellent audio quality.