Because of differnt water quality in different places, the faucet is more eaiser to get clogged in public area which is more frequently use and lack of maintainance.  When the aerator getting clogged, the watering effect of the faucet getting worth and will need to change a new one when it's getting too much limescale and impurity So this is why we develop this brand new reversing faucet aerator, it can adjust angle from 0-180 degree