Shower flow restrictor

thingiverse

Insert a device that reduces warm water flow up to 30% into the shower system. Place it between the water tap and the hose leading to the shower head. This simple solution costs less than one cent, yet can save hundreds of liters of warm water each year. You'll hardly notice any difference in comfort level due to varying water pressure, shower head designs, or personal preferences. To fine-tune the device, simply adjust the diameter of the central hole for optimal results. Give it a try and remove it if you're not satisfied with its performance.