Netvox wireless dry contact sensors can be used to detect contact between two wired contact points. It can realize wireless alarm and other functions through built-in wireless module, and is compatible with LoRaWAN protocol. It can be easily networked with other related devices. The R311CA is durable and ensures optimum use and is a low power consumption device. Due to their small size, they can be installed anywhere, they are wireless, so they take up very little space.