What does the water release controller switch do?

The water release controller has 4 different preset’s on the rear of the product, that can change the amount of water being released out of the cistern into the pan. There is a 5th preset that the water release valve can be tricked into releasing, which will not damage the product. The 4 standard presets are 4.5 litres, 6 litres, 7.5 litres and 9 litres, with the additional 3.3 litres that can be achieved also.