What is installed on the door of the positive isolation house in Fuzhou Drum Tower?

Electronic door sensor. The white thing installed at the isolated door is an electronic door sensor, which is a security alarm device. It consists of a wireless transmitter and a permanent magnet. It is used to detect whether doors, windows, drawers, etc. have been illegally opened or moved. It is divided into wireless There are three types: door sensors, wireless rolling door sensors, and wired door sensors.