LOPURS Real-time Tracker & Door Alarm / GSM Independent Multi Function Monitor, the Door Was Opened / Closed, Will Send SMS and Call You. Quad Band, Network: Gsm850/ 900 / 1800/ 1900mhz, Work in All Europe Countries Simple operation,without install The door was opened/closed, will send SMS and call you. Active listening Quad band, Network: GSM850/ 900 / 1800/ 1900MHZ