Smart AWC touch is the most compact auto water change system. It uses two super tiny uniquely designed optical sensors that are suitable for both small and big tanks. Doing water change becomes so simple with Smart AWC touch. Magnetically-coupled sensor makes it so easy to adjust to the desired water level. Simply mount the two sensors on your tank, adjust their heights with the magnetic mounts and program desired auto water change process by the touch screen. You can even select AUTO mode to do water change automatically at desired frequency and speed. Integrated with QST (Quick Security Technology), which provides real-time fail safe protection against any failure and detects water empty. Best of all, it also has ATO function to maintain the water level and salinity.