IMPLEMENTATION: Victor Papanek, an American industrial designer, came up with the dual flush idea in his 1976 book “Design for the real world.” Australia was the first country to use it in 1980.

GET SMART: Flush the toilet according to your needs the next time. Use the smaller lever if you only urinate. It may have a little size or an image that identifies it as the small flush, like a half circle, a small raindrop, etc. The larger lever, which will again be larger or have visible indicators, must be pressed only when you are ready to take a crap.

IT IS FOR WATER CONSERVATION: approximately 6 to 9 liters of water can be flushed out with the bigger lever, while approximately 3 to 4.5 liters can be flushed out with the smaller lever. Solid waste flushing is obviously the larger one, while liquid waste flushing is the smaller one.