Water saving shower type aerator converts existing tap to water saving taps. This may be fitted for allmost 90% of exisiting brand basin taps, Sink taps which comes with aerator option. Quick and straightforward to install and clean without any help of a plumber. There are 2 model green, 2lpm and blue, 4lpm. Depends upon flow rate you can select the model which can save up to 80% of water. The mechanisim inside has been crafted to adjust itself the flow rate to optimum flow rate and the outside of the aerator is designed to give a feel of a shower in taps. Save water to save planet earth