Toilet Water Saver Fill Cycle Diverter, Saves 1/2 to 1-1/2 Gallons of Water per Flush Diverts the some of the water that normally flows down the toilet overflow tube back into your toilet tank during the toilet's filling cycle Save 1/2 to 1-1/2 gallons of water per flush It fits onto the fill hose and clips to the fill tube. This is not a flow restricting device and will not effect the flush power of the toilet. No tools needed to install and there are no adjustments required.