One litre is your limit.
Theory say we waste almost six liters of water and use only one, while washing hands. Regarding it there’s a new curious, but obvious tap. Designed by three young chinese fellas: Yonggu Do, Dohyung Kim and Sewon Oh, this new tap has a tube on it, where you can only use one litre each time you open it. But it is not like those taps that stay leaking for 30 seconds. You may close it if you use less than a litre. And that’s the innovation feature of this taps.