Adopt the GSM network, no distance limit when alarming. Can surpport the GSM mobile phone, with sending 3 short English messages function. Can store 3 alarm phone numbers, which can send to the owners, policeman and the monitoring center. Long distance to arm/disarm/panic alarm/monitor, monitor function: the people can hear clearly the voice on the spot. The owners can control the small household through the mobile phone or telephone when they are out.