Wireless GSM Alarm for containers. These battery powered container alarm system will contact your phone by call or text message alert when a burglar or intruder is detected by movement or door opening. Metal shipping containers often hold valuable items, tools or stock. This makes them a target for thieves. Suitable container alarm have to be able to work without mains power and send intruder alerts to your mobile phone. A difficult part of finding the correct container alarm system is dealing with the metal construction of the shipping container. Our range of wireless GSM container alarms have vandal proof external antennas to overcome this issue and secure your shipping container and its contents.