https://www.thethingsnetwork.org/device-repository/devices/dingtek/df200/
DF200 - Soap Dispenser Level Sensor | Device Repository for LoRaWAN
The CNDingtek df200 is soap dispenser level sensor, which detect the liquid level in the dispenser.
dispenser level sensorsoap
https://www.thethingsnetwork.org/device-repository/devices/dingtek/df400/
DF400 - Tissue Dispenser Level Sensor | Device Repository for LoRaWAN
The CNDingtek df400 is tissue dispenser level sensor, which detect the paper in the dispenser.
dispenser level sensortissue