The CEITCON SN-M2 is a smart NB-IoT door sensor designed to provide reliable real-time monitoring of doors, windows, cabinets, and other access points. Leveraging NB-IoT connectivity, it delivers instant status updates and remote alerts while maintaining low power consumption for long-term operation. Its rugged industrial enclosure and external magnetic contact make it ideal for security, asset protection, smart buildings, warehouses, and industrial IoT applications. The sensor is easy to deploy and enables dependable remote monitoring without the need for complex infrastructure.