Most low-flow showerheads use 1.5-1.75 gallons per minute--much less than the 2.5 gpm in standard showerheads. The lowest flow showerhead on the market is only half a gallon per minute. By injecting air into the shower stream, these stylish water savers still deliver a comfortable, powerful shower. Visit the WaterSense program through the US EPA:
http://www.epa.gov/WaterSense/products/showerheads.html