R718VB can detect the toilet water level, hand sanitizer level, presence or absence of toilet paper, it may also be applied to non-metallic pipes (pipe diameter D≥11MM) liquid level detector. This device is connected with a non-contact capacitive sensor which can be mounted to the exterior of the container, without direct contact with the object to be detected, which may detect the current position of liquid level, or the presence or absence of liquid soap, toilet paper; the detected data is transmitted to other devices through the wireless network. It uses the SX1276 wireless communication module .