The S3524A is designed for house and office and other applications. It based on GSM Communication network and Lcd Menu display technology. When any sensor triggered, it will Call&Send SMS to user cellphones. Also, the Child Remote Control recognize function is our unique technology, When the Child press his remote control button, the mainframe will send a SMS "I’m leave home now" or "I’m come back home now" to his father or mother! The S3524A equips with LCD and Operation Menu Display, all operations and settings are visual and intuitive! What you need is a SIMCard which support Call ID function. Functions & Features: Tri_band 900/1800/1900MHZ; Can arm or disarm by SMS or remote control or mainframe keyboard; Automaticed send SMS Alert to pre-set cellphone when it triggered; Automaticed dial Pre-set alarm phone numbers when it triggered; Supports up to 15 pcs wireless sensors, each sensor can be named by user; Supports 3 alarm telephones; Supports Pre-set Message, Message inbox, Message Outbox, etc; With Handset and dialer, the functions like the Cellphone; Supports wiretap through internal Mircophone; Supports SMS Operation report, when armed or disarmed by SMS, the mainframe will reply a SMS to user’s cellphone;