This tap aerator is incredible, but simple in the same time. Working as normal water saving tap aerator, has got one more extra feature which is the magic button located in the centre of water flow outlet. This button will let you stop the water flow at any time by touching it. now imagine how much water is being wasted during the normal washing dishes duty. Imagine that half of time when water is flowing during washing dishes process you son't need to use water at all! So why not just move your hand and touch the button when water is not required? You can control the water on and off just through touching the button of the aerator. Installation is very simple and not require any special tools. There is also another extra. How many times you wanted to turn the water off but you haven't done it because you hands were greasy or dirty. this problem is gone as well now as you don't have to touch your tap any more. The Start/Stop water aerator will fit all standard 24mm male compatible taps. The set also comes with 24mm male to 22mm female adaptor.