These tap aerators are a simple insert for your existing tap fixtures. They will reduce basin water usage costs by up to 70%.
My own water bill greatly reduced after intallation in Mid Aug.
How does Tap aerator works:
1) Restricts the flow of water from your tap without reducing water pressure.
2) Comes with replacement washers.
Installation is easy.
Installation of your new water efficient tap aerator is simple. Just follow these steps:
2) Assemble your new aerator by placing the insert and new washer (included) into the housing.
3) Clean the thread on your tap.
4) Screw your new aerator on and hand-tighten.
Here's a YouTube video showing the above process (American installer, but it's just the same here!):